​If you cannot convince them, confuse them. This is the basic for selling lies. And very basic for anonymous SIM card scam.

​There is no way to make a phone call from your cell phone without a SIM card, unless you are calling emergency numbers or you are using app voice calls via WIFI (as Skype or WhatsApp). But because scammers are trying to sell you a SIM that pretend to be "anonymous", that SIM might use a cell tower. Also, even when using data voice calls instead of regular voice calls, your phone will connect to nearest cell tower (data connection channels instead of voice channels). Unless using WIFI, there is no way to circumvent a cell tower if you want to communicate. A cell tower means mobile network, servers, SS7 vulnerabilities and exploits, IMSI Catchers, GSM Interceptors, location tracking and monitoring. Least but not last, mass surveillance.

​Are you a happy buyer of one of those Anonymous SIM cards? Are you sure that IMSI is protected and your SIM security is "hardened"? Well, time has come now for a small and quick test.

Most of people have no idea what IMSI is, and also no idea on how to get it from their own SIM card. Moreover, they have no idea what can be done when someone is getting IMSI from your SIM card. So let's start testing. No need for any technical skills, special knowledge or payments.

​Anonymous SIM card vendors pretend that card security is "hardened" and IMSI is not revealed to interception systems due to some security tricks.
Whether you have a classy Android or swanky iPhone, you can test your new bought "anonymous" SIM card, right now. Just go to Google Play or App Store and install any app that shows your SIM card info. Example: Whats My IMSI.
On iPhone is even simple: go to Settings menu and from there you pick "Mobile Data". Choose "SIM Applications" and that's pretty much you have to do.

Got your IMSI now? Good. Now you can throw away your "anonymous" SIM. And have a look on your window: your "protected" calls might actually "call" the police straight in front of your gaff.

The IMSI you can see is being used by your phone when connecting to any cell tower, in order to make/receive calls and messages. There is no other way around. The phone cannot connect directly to any "telephone switchboard", as scammers pretend. Because "telephone switchboard" is not a cell tower. Your phone call is routed first trough local mobile network, then trough SS7 network, to recipient mobile network. In this particular case, your phone call is also routed trough your "anonymous" SIM issuer servers located in Russia, before reaching recipient local network. Hence, instead of "hardened" security you've got less security than you have expected. And sure, with an extra payment which will make you think that is serious yet affordable security.

Google for SS7 attack, SIM Toolkit attack, IMSI Catcher to see how IMSI can be retrieved over the air and then what can they do with it.

​Buy cheap pay as you go SIM cards and sell them as anonymous SIM cards, with 500% profit margin.

Straight forward: there are no anonymous SIM cards. This is technically impossible. All of them are just a big time scam that take advantage on lack of knowledge from regular people. And nothing more.

Fact: there is no SIM card without an IMSI.
Fact: there is no connection to a cell tower without IMSI being used for connection purposes.
Fact: even data only SIM cards have an IMSI assigned by the manufacturer.
Fact: there are so called IMSI catchers, designed especially for call/SMS interception based - as its name says - on IMSI.
Fact: if you can call whatever number or you can receive calls, that means your phone is connected to a cell tower, by using voice/data channels.
Fact: once connected to a cell tower, almost ANY cell phone location can be (and it is) tracked by various technologies and systems, taking advantage on mobile network weaknesses or mobile network nodes (SS7).
Fact: once connected to a cell tower, any phone call can be (and it is) intercepted, no matter if voice call is routed on standard voice channels (regular voice call) or on data channels (as Skype, IM, WhatsApp, etc.).
Fact: not the SIM card is choosing the cell tower to connect on it, but the phone. This is the way that all mobile networks are designed (no matter if 2G, 3G, 4G, etc.), a SIM card being only used to identify a certain subscriber.
Fact: the phone number is not stored on the SIM card. Phone number is stored on mobile network servers (HLR/VLR) and cannot be altered/changed directly from the phone/SIM. A phone number can be altered/changed ONLY by using data connection and 3rd party servers. Some particular "russian SIM cards" are using standard voice channels that still route the call trough some russian server, where in fact take place voice changing, and only then the call is routed to call recipient.
Fact: ANY SIM card is encrypted by default, using comp128 algorithm. There is no other encryption that a SIM card support. This is meant for anti-cloning purposes. Some early comp128 versions has been compromised, old SIM cards (until 2012) being easy to clone.
Fact: ANY regular phone call on ANY mobile network (no matter if 2G, 3G, 4G, etc.) is encrypted by default. Otherwise, anyone with a radio receiver can intercept that call. A SIM card CANNOT ad another layer of encryption on top of existing one, nor additional encryption.
Fact: ANY SIM card is trackable and any phone calls and SMSs done with a SIM card can be intercepted.
Fact: IMSI is not the same with phone number, nor with ICCID. IMSI is stored on SIM, since phone number is stored on carrier servers.
Fact: IMSI is not printed on SIM, but ICCID.
Fact: anyone can figure out its own SIM card IMSI, by using freely available apps (both on Google Play and App Store). If you average Joe can do this, then law enforcement or hackers can do that remotely, over the air.
Fact: IMSI change is possible by sending special requests to SIM issuer (the mobile network that issued that particular SIM). The request cannot be sent directly by the SIM user but by other company, in his name (used for example when porting a phone number). Changing IMSI this way is not a standard procedure, despite the fact that IMSI change is mentioned on GSMA and 3GPP procedures. Fraudulent MVNO companies (mostly russian) are taking advantage on this procedure, enforcing the law because the MNO doesn't care, changing SIMs IMSI based on user direct request.

Started back in 2014, anonymous SIM card scam refers to a few types of SIM cards that are being sold to people without a decent knowledge regarding mobile networks:

1. Pay as you go SIM cards (aka prepay SIM)

Some European countries as well as non European ones still issue pay as you go SIM cards with no need to show any personal ID and with no prior registration. This type of SIMs are considered "anonymous" just because there is no connection between user name and phone number. There are no other "special" features or "security hardened" things, whatever that means. At first sight, using a pay as you go SIM (eventually issued by a foreign carrier) looks as an advantage for SIM user. But stepping down on real life, this is what is happening: when a suspect is using whatever SIM, law enforcement ground teams are using IMSI Catchers and/or GSM Interceptors that collect both SIM IMSI and phone IMEI, for further tracking and monitoring. Hence, doesn't matter if the suspect is using a pay as you go SIM: IMSI catcher has done the job, matching all together: suspect identity, SIM identity (IMSI) and phone identity (IMEI). Simple and effective. A good article regarding this type of anonymous SIM scam can be found here.

2. SIM cards that have so called "multi IMSI" option.

This is nothing unusual, and are not adding any additional security to phone calls or location tracking. Just google it by yourself. Multi IMSI SIM cards are sold worldwide by various carriers as SIM cards for frequent travelers which can have up to 4 different IMSIs, corresponding to 4 different phone numbers. The user can choose which IMSI (phone number) is used at a time, by local low rates policies. Nothing to do with additional security or dynamic IMSI change. This type of "anonymous" SIM cards create a false security feeling just because user can alternatively choose from 4 phone numbers to use. Any multi IMSI SIM card can be tracked and intercepted as any other SIM card.

3. Russian "anonymous" SIM cards.

These are SIMs issued by russian MVNOs, which have assigned 1 or multiple IMSIs (up to 4). To place "anonymous" calls, the phone (along with the SIM) will connect to the closest cell tower, by disclosing both IMSI and IMEI. There is no other way around. IMSI and IMEI have to be used in order to connect to the network. Hence, no anonymity: since IMSI and IMEI are disclosed, a wide range of tracking procedures (SS7, GSM Interceptors) are possible, also call interception and SMS interception are just a kids play. Going further, the call is rooted from local mobile network (which is the first weak link that instantly disclose user identity), to russian MVNO servers, where phone number and voice are eventually changed (if user choose to use voice changing and phone number changing), and then the phone call is finally reaching the recipient number. What this clowns are trying to hide from you by taking advantage on your lack of knowledge regarding GSM network standards and specifications is the call route: instead of standard call route (simplified: cell phone > cell tower > core network HLR/VLR > network switch SS7 > russian MNO > russian MVNO servers > russian MNO > SS7 switch > recipient network HLR/VLR > recipient local cell tower > recipient cell phone), they claim that the call originating from your cell phone does not connect to any surrounding cell tower but to some sort of "telephone switchboard", which obviously is not technically possible. Do not forget that even when using data connection to place a IM call (Skype, WhatsApp, etc.), your phone will connect to THE CELL TOWER, by using the same IDs: IMSI and IMEI. In other words, unless you are using WIFI, any call will go trough nearest cell tower, no matter which SIM you are using. With a lot of nonsense blah blah and using apparently a technical vocabulary just to make you think they are professionals and/or skilled hackers, a vocabulary that in the end of the day will probably convince you by confusing you, scammers succeed to sell SIM cards as "anonymous" SIM cards.

We all know that SS7 network is compromised, but it takes more than a few keystrokes to abuse the SS7 network: it takes expertise, money and more important - SS7 access. But from what we have seen, once attackers have all 3 they are making sophisticated use of SS7, because once you have this ability, you want to exploit it fully. The real problem with these unscrupulous russian MVNOs is the access they have to SS7 nodes based on contracts they have with other international carriers, access that make available for them a wide range of SS7 exploits, including call interception and location tracking.

 * Anomalous, but not malicious traffic. This can be everything from malfunctioning nodes, attempting to send for all subscribers rather than their own, to unusual implementations of legitimate services, to anything else which is not known to be malicious. The skill here is in identifying this and making sense of what is malicious and what isn’t – not always easy to understand.
 * Malicious attacks, up to a medium-level complexity. These are the more well-known location tracking, fraud and information harvesting attacks, and were the main type of attacks that operators encountered when they started to investigate SS7 security in depth. As time has gone on, the perception of ‘simple’ has risen in complexity to cover more and more types of attacks.
 * Malicious attacks, of advanced complexity. This is the type of attack that takes investigation to even identify in the first place, and once identified requires detailed understanding of what the attacker is trying to achieve and how, in order to build consistent defense against it. These are the most advanced type of attacks they will increase in complexity as time goes on.

We are actually seeing a progression over time (i.e. over the last 2 years), where some of the attackers who have access to the SS7 network have progressed to trying to use more and more sophisticated methods to achieve what they want, especially now that a large number of operators have begun to implement defense. Most relevant example: ULIN.

One more thing: as always when something is too nice to be true, you never know who is really hiding behind that servers. You have no means to check that russian MVNOs and its hidden strings that eventually lead to local intelligence services.

4. Writable/Programmable blank SIM cards, widely available on Alibaba and other Chinese web shops, also on eBay and Amazon, at really low prices that comes in bundle with read/wright device and software. This way, you can make your own SIM card, with any IMSI.
This is all you need:
a. A programable blank SIM card
b. SIM card Reader/Writer device
c. Software (usually 128k Milenage algorithm and XOR algorithm, Matching the standards of GSM11.11, GSM11.12, GSM11.14, GSM11.17)
The (big) problem consist in Ki (encryption key) which need to be written on that new SIM. You need to know the Ki key, and there is no way to retrieve this key 99.9% of the time from another SIM card, because it is only known by the operator itself. This is why SIM cloning (comp128 v2, v3, v4) is not successful.
Ki problem can be easily solved by a malicious MVNO, which know the Ki and can program its own blank SIM cards.
Chinese vendors has solved this: SIM factory can program the SIM for you when ordering in bulk, including custom printing as you can see on most "anonymous" SIM cards. See it in action:

​Even if Ki is known, once written, the new "anonymous" SIM card will encounter real security issues that make it more vulnerable than a regular SIM, nulling this way the IMSI change function:
a. does not support GSM 11.14: digital cellular telecommunications system (Phase 2+) - specification of the SIM Application Toolkit for the Subscriber Identity Module - Mobile Equipment(SIM - ME) interface.
b. does not support GSM 03.48: security mechanisms for SIM Application Toolkit - Stage2 (GSM 03.48 version 8.8.0 Release 1999).
This mean that the SIM card is vulnerable to a wide range of remote SIM Toolkit attacks.
c. comes with STK menu that supports various applications, which can be updated by OTA download. That means you are not in control of your "anonymous" SIM card: various and potential dangerous executables can be downloaded and executed on your SIM, without your consent and acknowledgement.

Just google it. Crowds of scammers using tens of websites, eBay and Amazon accounts are trying to scam you big time with "anonymous" SIM cards. You can even call them, asking more explicit about how anonymous SIMs work. No doubt, you will get as many explanations as scammers are. Every single one will come up with his own evasive explanations, sometimes even hilarious for an advised person. Those are "professional experts" type. The other ones - "honest" seller type - will simply reply that they are only selling those SIMs, and more explanations can be found on manufacturer website.

​Judging only by the number of items sold via eBay and Amazon, there are thousands of fooled people. And their number is still on the rise.

Beside billing, phone number changing is a feature that work. On the other phone you are calling will appear always another phone number that is calling. At first sight, this is a stunning security feature for most of users, which will certainly impress the buyer that can see a live demo of the feature. But:
Phone number changing take place on their servers, so the phone number will be changed only when routed call will arrive on their servers, on its way to called cell phone. The call is leaving your cell phone with the same IMSI and phone number every single time, and changes are done only when your phone call hits the server.
From the point of view of an IMSI Catcher or SS7 attack, NOT the phone number is relevant, but the IMSI. This is why interception systems are called "IMSI Catchers" and not "Phone number catchers".
And yes, your cell phone location can be tracked and your calls can be intercepted as any other ones. From law enforcement point of view, changing phone number have no relevance when it comes to call interception and location tracking just because the phone number is NOT STORED on SIM card. Phone number changing is actually the single feature that can be tested by the user, which will convince any skeptical person to buy a anonymous SIM card.

Find out more

source

​Back in 2014, some Russian white hat hackers have revealed Anonymous SIM card scam. Read below their study and conclusions.

​"If encryption made any difference, they wouldn't let us use it", said someone.

Encrypted calls are protecting you from the ones that don't want to (or cannot) intercept your phone calls, and does not protect you at all against the ones that can intercept your calls - law enforcement, homeland security and intelligence agencies. Make sense to you? If not, please read below.

Most people think that call encryption is the Holly Grail of secure communications, being also a mainstream when it comes to software development for mobile security. Why is that? Because of 007 movies? Not at all. Because is the only product you can find on nowadays security overcrowded market. From hardware devices to sophisticated software applications, all claim that encrypting your mobile voice calls is the best you can get and there are no other trustworthy solutions. Unfortunately encrypted calls does not offer real security when you are targeted not just by (abusive or not) law enforcement, homeland security or intelligence agencies, but worst, even when you are a target for a skilled hacker.

You don't have to trust us. Just google for voice call encryption hack and tons of articles are available at a glance.

For those of you that use voice encryption products on mobile phones the last thing you would expect is for it to be easily decrypted and intercepted. You may have shelled out good coin for your application and rely upon it for your intellectual security, but what if that security was not as tight as you had imagined, what if a readily available wiretapping utility attainable by anyone, and a simple Trojan slipped on to your device could compromise all of your calls?

Back in 2010 blogger, hacker and IT security expert Notrax has done just that. For his own safety we will not reveal his name, however, Notrax has discovered that 12 commercially available mobile voice encryption products can be intercepted and compromised using a little ingenuity and creativity as he has carefully detailed on his website.
He tested 15 voice encryption products in total, 12 of them were “worthless”. It’s easy to take the software at face value when it “tells you” that the call is secured. But how does someone actually go about being sure that it is secured? Notrax did some digging and discovered he could break in to almost all of them in under 30 minutes.

Secure means that Notrax did not manage to crack it. It does not mean that someone else would not be able to crack it.

These calls can be tapped by anyone that has basic technical skills or the money to back up such an endeavor. “Statistics show Government agencies on average conduct 50,000 legal wiretaps per year (legal= those where a court order is required), (Let’s not forget Echelon) another 150,000 phones are illegally tapped by private detectives, spouses and boyfriends and girlfriends trying to catch a potential cheater. Another estimate shows up to 100,000 phones are wiretapped by companies and private industry in some form of industrial espionage. It is happening and it is a big business.”

SnapCell was safe, it’s a private encryption device that snaps on to your mobile, they claim to protect your mobile voice, fax and data communications from wiretapping, eavesdropping and line interference. SnapCell’s website has been offline since January 21st for unknown reasons.
If you are using one of the above voice encryption technologies, you may want to be on the lookout for a new solution, as XCell Stealth Phones. Although these applications cracked are not entirely secure, it would take much effort to bypass them, like having the attacker be able to load software or a trojan on your phone without you knowing. It’s similar to a credit card, so as long as you keep it with you in a secure place you should be fine for the most part.
How govt is using spyware to circumvent call encryption? Read more here.

Think that LTE mobile networks are secure? Well, think twice: hackers decrypt VoLTE encryption to spy on people calls. More here.

Though using of encryption to protect your privacy might be the prudent choice, the method has its own disadvantages:

• Because a cell phone (no matter brand, OS, ram or chipset) does not have enough computation capabilities to encrypt/decrypt a phone call locally, voice encryption take place on 3rd party servers. That means your voice encryption app that you just installed on your "secure" smartphone act like a link to encryption server. This way, only by using data connection (WIFI, etc.) and stepping out on phone outer world you can use such application. The problem is that a server is actually someone else computer. You can't find out who is really hiding behind that servers. Some manufacturers of cryptographic equipment have a track record of hidden cooperation with intelligence agencies and interested private companies. Some of them are not even using publicly scrutinized and standardized crypto algorithms (like Diffie-Hellman, SHA256, AES and Towfish), but “proprietary” encryption methods that are not available for public evaluation. Several “proprietary” crypto-algorithms that were not subject to public review have been shown to be easily breakable in the past, like the COMP128 algorithm that is in use in many GSM networks for authentication, so the “proprietary crypto” approach has to be regarded as very risky. In the end of the day that means you have no real control on your voice calls.
• Introducing a back door into a crypto system does not even require active cooperation of the manufacturer of the equipment or software. All it takes is one bribed programmer to compromise an entire product.
• You never know if encryption solution you use is indeed trustworthy and there is no reliable way to check it. Most of the encryption applications developers are not making public the source code. There can be (and most of the time there are) back doors used by law enforcement agencies. Sure, you can find source code for some encryption apps, which are made available for public by the developer itself. Unless you are not a cryptographer or cryptanalyst, there is no way for you average Joe, to find out if some security flaws affect your encryption app.

Open sesame of encryption solutions
Will you use an encryption app that have servers located in let's say... North Korea? Probably not, but you have to reconsider your opinion. Shortly saying, the more consolidated a democracy is, the easier is for law enforcement to get access to encryption servers, based on a simple warrant. All that because consolidated democracy countries know what we call the rule of law. Since encryption apps are not developed out of this planet and all encryption servers reside in some county, Govt and related institutions have a simple tool called judge warrant which will instantly "open" any "encrypted" server used for so called "secure" communication. Yes, its a matter of time. But in the end they will get a plain text or plain voice copy. Not to mention that NSA and other similar actors have tools and solutions that effectively circumvent any encryption apps, used nowadays to find out in real time what they are looking for.

Using voice call encryption might make you look suspicious and attract unwanted attention on you, exactly from the ones you are trying to hide from. Its like a ringing bell attached on your tail. Have a wild guess on what they will do in case the you use an encrypted cell phone. For sure they will use some other ways to get the info they need. They will not wait to find some security flaws in your crypto app, they will not attempt even deciphering. They will simply bug your home, office and vehicle, will spy on your computer, will intercept your mail and will use covert human intelligence sources (HUMINT) and whatever it takes to obtain relevant information about you and your activities. They can easily bypass the communication protection provided by the encrypted phones by simply collecting relevant information from other sources. Simple as that. Yes, its not on real time. But can be very close to that.

If you are targeted by an intelligence agency, encrypting your mobile communications does not mean that you are 100% protected against eavesdropping. Think about that: will they drop you just because you use encrypted communication? No, for sure.. Being a challenge for them, will find another ways to get the information they need. Sure, for a short period of time your secrets will remain... secret. But any decent agency will find at any time security breaches, gathering info they need about you, by any means.
Actually by encrypting your phone conversations, you are telling them that you have something important to hide and you invite agencies to use other ways to gather intelligence.

When using encryption over standard mobile network voice channels (not via data connection) like that encryption devices attached to your cell phone, that encrypted call is not so... encrypted as you think. Yes, will defend against call interception performed by spyware apps installed on your phone, because phone microphone is not used during encrypted call sessions. But even if you use such a device, the GSM operator or the entity that operates a GSM interceptor can find out pretty much information such as:

• both phone numbers involved in conversation
• conversation length, time stamped
• your (phone) location at the moment of call
• your geo-location at every moment, by some simple and effective triangulation techniques, based on your phone IMEI that cannot be hided by any encryption app. Once you power up your crypto phone, IMEI and IMSI (if there is inserted a SIM card) will be sent out to network, for connection. No need to make any call or send any SMS. This is the way that all cell phones work, including your crypto phone.​

• Modern GSM interceptors can selectively and temporarily block any cell phone within its range based on IMEI and/or IMSI values, making that particular crypto phone unavailable for use, for as long as they want. This happen when a crypto phone uses data connection in order to make encrypted calls.
• It is well known that cell voice encryption need high speed internet connection. Many modern GSM interceptors can downgrade your crypto phone connection from 3G/4G to 2G, by simply jamming 3G/4G uplink frequencies, which is a standard procedure. By doing that, crypto phones that use data connections will fail and become useless.

Not even notorious encrypted cell phones are immune to this attack. Few years ago, an average Joe posted on YouTube a short movie demonstrating how a well known app used for enterprise encrypted communications - GoldLock - can be defeated by a cheap commercial grade spy app called FlexiSpy. Because he had the phone in his hands with GoldLock already installed on, he installed also FlexySpy on the same cell phone. He started an encrypted phone call with another GoldLock phone. Entire conversation was recorded by FlexySpy in clear, just because FlexiSpy collect audio straight from the microphone, way before GoldLock proceed to voice encryption. Then, when conversation finished, was automatically sent by FlexiSpy via WIFI or data connection on a server where could be listened from user personal account. Simple, efficient and embarrassing for a top notch encryption application. You can do whenever you want the same test.
By some reasons, the video was removed from YouTube so we cannot post a link. Also since then, no more free trial apps are available from GoldLock, avoiding other similar situations. However, that does not make GoldLock less effective for private users, being by far one of the most secure communication application.
And yes, the same can happen with your "secure" cell phone.

This is why voice call encryption is a short time solution for secure communications. In fact, being predictable is one of the worst choice on intelligence battlefield. And using a crypto phone means that you are more than predictable.
When using any voice encryption solution (software or hardware), you will never know when actually your cell phone is intercepted, and by consequence you will never know when you are in real danger. Instead of crypto phones blind protection, it is better to know when someone attempt to tap your calls and when they are trying to locate you. Then you can act advisedly, taking the right decisions and even influencing them by different deception techniques. Here comes XCell Stealth Phones, which brings you the best of both worlds: interception detection and interception blocking. Detecting interception in real time and on the right time is really something else than using blind encryption, an advantage that is used by professionals against... professionals.

Based strictly on customer request and if we are sure that customer fully understand all security risks he take, a voice encryption app can be installed on XStealth Lite and XStealth.

source

Surprisingly for most people, the phone number (called MSISDN in terms of mobile networks) is not stored on SIM card, which contain only SIM ID, called IMSI (International Mobile Subscriber Identity). By consequence, there is nothing that can be changed locally in a secure way, on SIM level. This is why XCell Stealth Phones can change/manipulate IMSI and cannot directly change phone number.

Hiding Caller ID is something else than changing phone number and depends on your cell phone and mobile network settings. The result is just a Unknown call received by the call recipient. Read more here.

At first sight, voice changing might look easy to be implemented on a cell phone, but real time voice changing needs powerful chip sets that usually mobile phones does not have. This is why all voice changing services or applications are using external servers or external devices attached to a cell phone. Hence, no real security for phone user.

A voice changer is not really necessary when it comes to phone monitoring done by law enforcement agencies: they will know exactly your identity, location, calls and messages path, the voice content of your calls and text content of your messages, etc. A voice changer will give you a false sense of security, unless you intend to use it for a prank. Also, in the past 3 years interception systems that use voice recognition feature for automatic target detection and call recording is not used as primary filtering tool, due to the fact that sample voice (needed for voice recognition) sounds different from phone to phone, due to different hardware capabilities. Hence, false positives emerging with an unwanted high rate. Read more here.

Before everything, let’s face it: who do you really fear?
There are not so many hackers around that can actually track your cell phone, because of few simple reasons: expensive hardware needed, lack of knowledge regarding GSM stack and SS7 protocol effective exploits, not to mention that hackers have no interests on you, average Joe. Excepting your worried parents and jealous girlfriend, no one wants to know your (cell phone) geo-location. Tracking a cell phone is not a simple “push button” situation when is done by a hacker. That involve deep and extensive knowledge, pretty expensive hardware, time and not least, an considerable interest on you, average Joe. Which obviously is not the case unless you are just another skilled hacker or a high profile person.
The situation became serious when you did something bad or even illegal. Then, you became a target for law enforcement and/or intelligence agencies. And there is no way to hide your (cell phone) location. They have not only the legal ability to track down your cell phone at any time, but have also technological and human resources to do that, not to mention training and expertise.
In case you think that your own cell phone is secure, its time for 2 simple tests.

TEST No. 1: NETWORK TESTING BY EMERGENCY CALL.

Read more here.

To be honest with you and also with XCell guys, their old website doesn't look too nice. In fact the look was pretty obsolete with that old HTML version. But now everything is changed and you can navigate on a brand new web shop: https://stealth-phones.com
However, not the website look is important but the new products you can buy there, now without any sale restrictions as they had before on the old site (x-cellular.com).
There is also a page that we appreciate more than others: The Blog. After getting permission, we will start posting some interesting articles from their blog.

Before reading:
Please note that we do not sell any devices, this is not a web store. We are not related to XCell Technologies, nor a subsidiary. If you want to buy any Stealth Phones, please contact manufacturer.

XCell Technologies has launched on 1st January 2019 their new flagship product: XStealth, an epic Android based Stealth Phone. Announced as a game changer, XStealth is one of a kind Stealth Phone. No other "secure" mobile phones have the same special functions and capabilities as XStealth have. Now, you can stop hiding. Be invisible and fight back with XStealth Phone.

Mobile technology has never played a more important role in personal security and basic rights than it does right now. XCell Technologies is uniquely poised to address the dangers of mobile interception used illegally or abusively by state towards its citizens, following shortsighted policies.

The next big thing is here. There was no perfect Stealth Phone, until now. The upcoming generation of Super Stealth Phones has been successfully rolled out.

There's been a lot of talk about Android Stealth Phone since 2014, when XCell Technologies released their first Android Stealth Phone, under Law Enforcement Product Line. Took them 4 years to develop the most advanced, the most secure Stealth Phone they have ever built. Excessively tested on all major interception systems, intensively used by field operatives and confirmed by their main clients as the most suitable for covert actions, when being a step ahead your enemies can be the difference between failure and success.
Based on XStealth military version released back in 2014 and stuffed with new and unprecedentely special functions, XStealth is now available for public use.

What do you want from a Super Stealth Phone? Everything, probably. After all, it's about your security. Well, with new rolled out XStealth Phone, you've got everything. And the best is yet to come.

Android Super Stealth Phone comes now in two flavors. Since XStealth Lite has been built for personal use, XStealth devices are aiming professionals ranging from govt to law enforcement and homeland security agencies. XStealth Pro is also coming as top notch product.

You can read more abour XStealth special functions, below. We hope that will get out hands on new device soon, for testings and first impressions.

While the rest of the market is going one way, with text and voice encryption, XCell Technologies is going down another, to the heart of problems, sticking with privacy and security based on interception detection and fighting against interception by using quite the same network weaknesses that IMSI Catchers and GSM Interceptors use. XStealth Phones are actually the only ones that can effectively fight back mobile interception, by using both defensive and offensive security methods.

Get the most out of your Super Stealth Phone, with our breakdown of specs:

First, about XStealth hardware security.

There is a kill switch to self-destruct on command even if the phone is turned off. As no other secure phones, XStealth USB port is protected by our well known volatile security filters: any attempt to connect the device to any other external device (no matter if PC, service box or forensic grade equipment), other than its own paired charger, will trigger a self-nuke mechanism that literally fry the whole motherboard in the same way as USB Kill work.
Anti-tamper JTAG protection is also implemented: serial communications interface for low-overhead access without requiring direct external access to the system address and data buses are disabled by default at  serial interface level.

XStealth Phones use a Tamper-Resistant Platform: any unauthorized attempts to connect the phone to any external device will delete the keys that encrypt all sensitive data. A remote wipe function is also available.
Authentication to login to the phone uses multi-factor (MFA) technology, voice biometrics being one of them. Due to security risks involved by face and fingerprint recognition login, these options has been removed.

Trusted Execution Environment (TEE) uses encrypted memory and includes a hardware random number generator. Communication between the Secure Environment and the application processor is isolated to an interrupt-driven mailbox and shared memory data buffers.

There is also installed a Data Execution Prevention (DEP) technology to mitigate memory-based attacks. This defensive technology dramatically narrows the attack surface area for memory related exploits by preventing code from being executable in sections of memory that have specifically allocated for read only data. DEP support is a critically important defense when used in conjunction with Address Space Layout Randomization (ASLR). These core improvements make it more difficult for spyware to perform buffer overflow, heap spraying, and other low-level attacks. Therefore, even if an attacker succeeds in loading the spyware code into memory, the spyware code will not execute.

XStealth Phones are not susceptible to side channel attacks, including various forms of power analysis attacks to ensure the protection of cryptographic keys.

XStealth Phones has the ability to execute a secure boot based on using a hardware root of trust for checking and storing hashes or signatures of firmware and other software loaded starting with the initial BIOS.

XStealth Phones have separates CPU from Cellular Baseband, preventing this way external manipulation by baseband attacks.

Now about XStealth software security.

Today too many apps are engineered to collect and disseminate enormous amounts of user data—such as location, Web browsing histories, device-unique IDs, search terms, and contact lists – data they often simply don’t need. Some app providers also try to obfuscate their data collection functions to get around restrictions by marketplaces such as Apple’s that are intended to prevent abuse of APIs and ensure better privacy for users. For example, researchers have recently discovered hundreds of apps in the App Store that extract personally identifiable user information via private APIs that Apple has forbidden them from calling. The abuser that was singled out – a Chinese mobile advertising developer called Youmi – used simple obfuscation techniques and dynamic linking to get around the application vetting checks performed by Apple. Same for Android platform, on weaker Google Play Store.

XStealth Phones runs a special version of the Android operating system—XROM—that blocks many of the ways phones leak data about your activities. XROM is an Android fork developed by XCell Technologies; it uses Google’s code for the underlying platform, but skips Google Services in the same way Amazon’s FireOS does.
The connection between XROM and software applications is filtered by Secure X-OS bridge, keeping both firmware and software applications away from exploits. Obfuscated code is adding an extra protection layer.

XStealth Phones does have Android trackers disabled by default, leaving no traces on Internet.

XStealth Phones comes with preinstalled generic applications which we have modified certain features (like removing back doors used by law enforcement and some security flaws), adding a plus of security and privacy (especially for Yahoo and Hotmail clients). This is why we have blocked any OTA software update which can restore security issues. Software updates usually refer to compatibility with new Android versions, which is not  our case and will not impact application workflow.

Regarding anti-virus application and software updates:

XROM firmware is secure by default: no other software applications can be installed by the phone user (which have the phone on its hands) nor remotely, by obscure third parties or abusive law enforcement. Hence, no anti-virus software is needed. Also, XStealth Phone will not perform any OTA firmware/software update, which may lead to remote exploits. You have to understand our point of view and hopefully reconsider your approach when it comes to mobile security: XStealth Phones are not aiming average users. All our Stealth Phones has been developed for professional use: intelligence agencies, law enforcement and homeland security. All above entities does not relay on encryption when it comes to secure communications because of a simple fact: all mentioned agencies have legal access and gain information they need by using back doors provided right by the software developers. If there is no cooperation from developer, then they will use another effective methods to gain access to relevant info, other than the ones used by hackers. There are plenty of companies that provide a wide variety of methods to penetrate any system such as computers and mobile phones. FinFisher is one of them: "Our Deployment Methods & Exploitation Solutions cover the latest PCs, smartphones, tablets and most common operating systems." "FinFisher can be covertly installed on targets' phones by exploiting security lapses in the update procedures of non-suspect software." "The software suite, which the company calls "Remote Monitoring and Deployment Solutions", has the ability to take control of target phones and to capture even encrypted data and communications. Using "enhanced remote deployment methods" it can install software on target phones." FinFisher malware is installed in various ways, including fake software updates and security flaws in popular software. Sometimes the surveillance suite is installed after the target accepts installation of a fake update to commonly used software. The software, which is designed to evade detection by antivirus software, has versions which work on mobile phones of all major brands.

FinSpy is a field-proven Remote Monitoring Solution that enables Governments to face the current challenges of monitoring Mobile and Security-Aware Targets that regularly change  location,  use encrypted and anonymous communication channels and reside in foreign countries. FinSpy is bypassing 40 regularly tested Antivirus Systems. Hence, no point to install an anti-virus as you have mentioned. XCell Technologies have opted for another effective solution to circumvent malware and harmful software install.

Please see also this short movie regarding remote mobile surveillance by "updating" a BlackBerry cell phone application: https://www.youtube.com/watch?v=n5ZJUXweayo

Even worst, also a not so skilled hacker can easily remotely install a spy application on a mobile phone which will not be detected by any antivirus, by the same "software update" procedure: https://www.youtube.com/watch?v=LicdrZwmHQo

There is a FinSpy detection algorithm installed deep on XROM firmware that will not only detect any intrusion attempt, but will block any code execution.

Encrypted bootloaders comes as standard option.

XStealth Phones are also using SIM Toolkit inhibitor, a blocker for remote code execution via SIM Toolkit (used usually by both network operator and law enforcement).

XStealth Phones use adaptive security defenses, being ultra-secure and adaptive [personal] smartphones: we will install before shipping any software application desired by the buyer, but only after running a comprehensive security audit. We will refuse to pre-install applications that can affect user privacy and security, and phone functions. No file explorers will be installed, as well as forensic clients or modded applications.

There are also things that we will not make them public available, as encryption algorithms used and firmware source code, simply because for any cryptanalyst will be more easy to break encryption when used encryption algorithms are known.
Also, a user controlled source code is not an option for XStealth Phones: that might be a huge opportunity for hackers and state controlled entities to find exploits, remote install/RAT or spyware which in the end of the day will lead to no security.

Please see below a list of special functions and default software applications.
Special functions command panel is password protected, accessible only by dialing a secret code.

1. Calibrate. First time when you activate the phone, you should run Calibrate function: the phone will self-calibrate, testing GSM network and saving data regarding home network, which is a part of auto-learning process. It is essential to use a new SIM card (no matter if contract or prepay) and to be in a safe place (connected to a real GSM network).

2. IMEI Change function. The user can control the way IMEI is changed (after every event as phone call or SMS, on network/IMSI Catcher request, etc.), and also can define its own IMEI, performing this way different protection scenarios. More info on User Manual.

3. IMSI Change function. Once enabled, the phone will start SIM cloning, generating valid IMSIs which are used for the next calls and messages. There are no other cell phones that can perform IMSI change. Please note that no Internet connection, third party servers or special SIMs are needed. Also, no monthly fees or other strings attached. Will work virtually with any SIM card, but we recommend using MNO SIM cards.
NOTE: This function is not available for XStealth Lite

4. Mode: the user can switch between Hunting Mode (call/SMS interception detection) and Anti Interception Mode (no calls and messages can be sent or received as long as phone interception is active, no matter if GSM Interceptor or SS7 means are used).

5. A5 Alert. Once enabled all, phone user will be warned in real time if voice and data connections are intercepted.

6. Location Tracking Alert. Once enabled, the phone will warn if a location tracking ping is received.
Ki extraction alert: every time when a GSM Interceptor is trying to get Ki (encryption key stored on SIM card) by sending so called "challenges" waiting for SIM replies with parts of encryption key, for later Ki calculation.

7. Real GSM Location Spoofing. The phone user can choose which cell tower the phone is connected to. This way, any triangulation technique used for location tracking purposes will generate wrong results which leads to false location. For easy of use, Optimal location spoofing should be enabled: the phone will always connect to the farthest cell tower, no matter if stationary or on the move

8. Channel Lock. The user can lock ARFCN (uplink and downlink - the radio channels pair that cell tower communicate with the cell phone and vice versa) in order to block any forced handover (forcing mobile phone to quietly disconnect from home network and connect to a fake cell tower impersonated by a GSM Interceptor

9. C2 Monitoring. The phone will monitor C2 parameter (cell re-selection criterion), which is used by IMSI Catchers/GSM Interceptors in order to force cell phone connection. Will also look for neighbor cell towers identity. In case the phone is connected to a GSM Interceptor, no cell towers will be shown as neighbor towers.

11. Sandbox. A separate secure partition where IMEI engine, IMSI engine and other security related software components run smoothly, out of any interference and tampering possibilities. The user can check at any time the integrity of Sandbox and its components.

12. Network Scan. A live network monitoring tool, looking for IMSI Catchers/GSM Interceptors, SS7 based interception and other network anomalies. A real time interception detection function is also available. No false positives due to intelligent scanning mode.

NOTE: This function is not available for XStealth Lite.

13. LAC Change Detector. This is the Proximity Alert Function. The phone will detect any abnormal LAC (Location Area Code) when stationary, changes made only by IMSI Catchers/GSM Interceptors in order to force connection

All data regarding mobile network - including LAC changes - is saved in a text document.

14. Microphone Lock. User can lock the microphone at any time, preventing remote activation and listen in on the environment.

15. Camera Lock. User can lock the camera at any time, preventing remote activation for spy pictures/movies

16. On Screen Functions

For easy of use, main monitoring and warning functions are displayed also on the home screen. Since main home screen looks anonymous and like any other smartphone, by a simple screen swipe all monitoring functions will pop up on the screen.

Call workflow
Every time when user is making a call, the phone will check for standard GSM network encryption (A5/1) detecting if the call is intercepted off air (by a GSM Interceptor) or at network switch level (SS7), by pinging the network core. In case of call interception, the phone will display a visual alert.

There are also default applications installed on the phone:
 - Proton Mail
 - Proton VPN
 - Tutanota client
 - Telegram X
 - Hotmail client
 - Yahoo client
 - Microsoft Outlook client
 - PayPal client
 - Facebook lite client
 - Messenger client
 - Fire Onion
 - Orbot
 - Tor
 - Orfox
 - Anti-theft security & alarm
 - Security Lock
 - Secret Photo Video Locker
 - Open Signal -  a comprehensive cell tower locator
 - Burner: temporary disposable phone numbers

Recently browsing eBay, we have discovered 2 old scammers located in the UK, that are using 2 new accounts, selling fake stealth phones since 2011:

• spdirect
  
• witz.end.solutions

Here is the fake stealth phone type sold by spdirect on eBay:

And here is the fake stealth phone sold on eBay by witz.end.solutions:

What you have to do, just to make sure you will not buy from a scammer, a fake stealth phone? Nothing complicated: avoid fakes by buying from official distributors or directly from manufacturer.

If you are either super important, super paranoid or a super spy, there are times when you need to be able to use a cell phone and not leave a trace or any chance to anyone to intercept your calls and text messages, including law enforcement and intelligence agencies.
 
Secure = encryption? Well, think again...
 
Nowadays, interception issue affects most of the people, even if they are not aware of it. Not to mention so called “off air GSM interception systems” or also known as “IMSI-catchers”, "GSM Interceptors" or "StingRays", it has been known since 2014 that using the legacy SS7 (Signaling System No. 7) protocol SMS based traffic text messages can be easily intercepted by using diameter based networks independently of device or OS type. Signaling System No. 7 vulnerabilities are easy to be exploited even by hackers, being a 50-year old protocol that is probably part of a majority of cell phones and text messages in the world.
Generally speaking, most of aware users regarding cell phone interception by above technologies, believe that using encryption solutions will secure their calls and text messages. It is encryption a real solution? Let's see...

Law enforcement, homeland security and other related actors have plenty of methods to intercept messages and read text content, even when using encryption. Ranging from SS7 exploit, encryption backdoors or intentionally weaken popular encryption algorithms to lawful hacking that circumvent encryption and hitech decryption technology, all are there at their fingertips.
 
Encryption will not protect your privacy. At all
 
Recent headlines warn that the government now has greater authority to hack your coell phones, in and outside the US. Changes to federal criminal court procedures known as Rule 41 are to blame; they vastly expand how and whom the FBI can legally hack cell phones. But just like the NSA's hacking operations, FBI hacking isn't new. In fact, the bureau has a long history of surreptitiously hacking us, going back two decades.
 
Back-doors provided for law enforcement
 
Encryption back doors remain largely viewed as weakening everyone’s protections all the time for the sake of some people’s protections on rare occasions. As a result, workarounds like the FBI found are likely to be the most common approach going forward. Indeed, in recent years, law enforcement agencies have greatly expanded their hacking capabilities.
Many reputable encryption developers and companies have chosen to retain the ability to read and use their customers’ content, or perhaps they decided there is not a sufficient business case to add end-to-end encryption or user-controlled encryption. Their users’ encrypted content is more readily available to law enforcement because they hold the decryption keys. The same companies offer their services in a way that encryption does not preclude their ability to hand over the content to law enforcement in response to a warrant. Are those services as secure?
 
Lawful hacking
 
Most of national security agencies had been shown to have immense surveillance capabilities actively deployed on a mass scale, especially in those countries where the functions of law enforcement and national security overlapped. Beside encryption master-key and built-in back doors that provide law enforcement exceptional access to anyone secrets and privacy, they now have unprecedented access to information through open-source intelligence, collection of metadata, sophisticated traffic analysis tools and data analysis algorithms. Many local and international laws are mandating insecurity by requiring government access to all data and communications that permits lawful hacking (otherwise known as encryption circumvention).
 
Encryption vendors and law enforcement work together to solve access "problem". One suggested fix is one way information sharing where vendors make law enforcement aware of unpatched exploits, allowing the government (and anyone else who discovers it) to use these vulnerabilities to gain access to communications and data. It's a horrible suggestion - one that puts vendors in the liability line of fire and encourages continued weakening of device and software security.  
Several individuals with backgrounds in security and systems have begun to explore possible technical mechanisms to provide government exceptional access.

XCell Technologies is really serious about mobile security, bringing you the most advanced SMS security solutions. Concerns about government mass surveillance and their ability to decrypt anything by using given master-keys, backdoors, lawful hacking or effective decryption solutions were the factors driving us to develop a brand new and 100% secure SMS communications which use not only strong military grade encryption but adding a new security layer by exploiting GSM network via MLSP®, to make sure there is no way to intercept text messages or metadata, even in encrypted mode. All above overleap existing commercial-encrypted apps, services, devices, and also law enforcement access to your sensitive info.
GSM provides by default only a basic range of security features to ensure adequate protection for both the operator and customer. Over the lifetime of a system threat and technology change, and so the security is periodically reviewed and changed here on XCell Technologies, and then applied on our products.
Taking advantage on GSM network architecture and SMS Transport Protocol, our SMS encryption technology is capable to send/receive encrypted and non-interceptable messages.
Our SMS encryption application called XCrypt use a groundbreaking multi-layer technology to protect SMS from being intercepted and decrypted. As a unique encryption application, beside strong military grade encryption, XCrypt use a brand new patented technology in order to send/receive encrypted messages: discrete GSM channels or Multi-Layer Security Protocol®. That will protect not just encrypted text messages but also metadata which is not encrypted.

Definitions

• "A-Party" phone is the sender phone which send encrypted messages via MLSP®
• "B-Party" phone is the receiver phone that will decrypt and display received message.
• Plain text message: a standard text message that can be read by anyone. Can be intercepted and read with no effort.
• Encrypted message: an encrypted text message that can be read only by using the right password. Can be easily intercepted in encrypted mode but cannot be read. A password is required in order to read the message.
• Metadata: data about data. SMS metadata is not encrypted because is not contained by the encrypted text itself, but law enforcement agencies are collecting unencrypted metadata to characterize the encrypted data. SMS metadata contain data about sender, receiver, message encoding (UTF8, UnicodeX etc.), date/time and length.
• Non-interceptable message: a text message (plain text or encrypted) which cannot be intercepted by any means.
• Real end-to-end encryption: no Internet and 3rd party servers involved.
• XCrypt: software application that use MLSP® in order to send/receive ultra-secure messages.

 
MLSP®
 
Multi-Layer Security Protocol - MLSP® consist in:
1. Physical layer: encrypted text message.
The phone will encrypt text messages by using following protocols:
• RSA
• AES 256
• Elliptic Curve (ECIES) 256
• SHA256
• Protected by ITSEC Evaluation level 3
2. Multi-layer routing and transport protocol. Encrypted SMS data is randomly segmented and distributed in bursts by Application Port Addressing Technology, via discrete GSM channels which usually are not "listened" by mobile interception systems (IMSI Catchers, GSM Interceptors or StingRays), both in air interface (UM Interface in terms of GSM networks) and Abis, A and C-G mobile network interfaces. This way, SMS data which is usually sent over GSM Layer 1 (and widely intercepted on Layer 1) will be sent by using a combination of GSM Layer 1 and GSM Layer 2 (LAPDm). By consequence, no mobile interception systems (as GSM Interceptors) and lawful interception systems (SS7 interception also known as network switch based interception or interception by the help of network operator) will be able to intercept the whole message but only a few bursts which are encrypted anyway.
3. Metadata protection. Regular SMS metadata is not saved in a separate file (called a metadata file). XCrypt separate metadata and the data it describes (SMS encrypted text), sending metadata file in bursts over the network, by the same Port Addressing technology. Metadata is of little value without the data file (SMS) it relates too. At the same time, metadata makes the data more usable and therefore, more valuable. An encrypted text message with separate metadata file will reveal nothing about SMS sender and receiver.

1. Phone level
 
At phone level XCrypt use a technology called port directed SMS, which is widely implemented in J2ME MIDP on mobile devices. The concept is basically that when an user send an encrypted SMS message to "B-Party" phone, a particular port number will be specified along with encrypted message, so only the device which is "listening" on that particular port will be able to receive an encrypted message. When a message is received on a port that the application is listening on, the message gets directly routed to secure Inbox instead of going to the standard message Inbox.
XCrypt will locally encrypt text messages at military level, then by message segmentation and Port Addressing will send randomly splitted bursts (bit streams) along with certain port address data by adding redundant bits to information binary string, to "B-Party" phone. Along with encrypted split message, the application on "A-Party" phone will send Port Addressing data, which will trigger opening certain Port Address on "B-Party" phone. This way, encrypted message will go through, avoiding standard phone Inbox and arriving directly on secure Inbox.
All this steps are transparent on receiving ("B-Party") phone, which also require user interaction which have to allow message to be routed to secure Inbox and decrypted by inserting the right password.
On "B-Party" phone, by port destination address, encrypted bursts will be selectively received, concatenated, decrypted and displayed only on "B-Party" phone which use the same XCrypt application that "listen" on certain receiving ports.
If on the "B-Party" (destination phone) is not also installed XCrypt app, then received message will not be delivered nor displayed by the phone (not even in encrypted/unreadable mode) due to Port Addressing technology which filter messages by port address.
When encrypting SMS, metadata file will be generated separately from text message and not as an integral part of the message as regular SMS do. Metadata file will be then truncated and sent in bursts over GSM network, by Port Addressing technology. This way no metadata can be intercepted by SS7 means.
At this level, handset vulnerability refer to forensic grade hardware and software that intend to extract system files and private data off the phone, including decrypted messages stored on XCrypt secure Inbox. XCell phones are protected against forensic procedures by USB volatile filters which does not permit any unauthorised USB connection, triggering motherboard self-nuke. Moreover, XCrypt run on Sandbox partition which is 100% encrypted and protected against file extraction by self-delete mechanism.
 
2. Um level
 
Um interface (the radio link between the cellular network and the subscriber handset) is the most vulnerable and exploited part of the GSM network by MItM attacks (IMSI Catchers, GSM Interceptors and StingRays), since no network operator help or target consent is needed. XCrypt will make use of GSM network architecture and SMS Transport Protocol in order to protect (already) encrypted messages to be intercepted even in encrypted mode. After encryption, the modulation signal has a carrier wave using GMSK (Gaussian Minimum Shift Keying) modulation. GMSK is a two-state modulation based on the frequency keying stroke.  
On Um interface XCrypt will use MLSP® technology: encrypted message bursts are not sent only on usual L1 SMS channels - SDCCH (Standalone Dedicated Control CHannel) signaling channels, but also on other available channels which are not subject of SMS interception, forcing Signaling Layer 2 (data link layer based on LAPDm protocol) for SMS Transport.
Since GSM Interceptors are "listening" only SDCCH physical channels in order to intercept text messages, will catch only a few encrypted bursts sent over SDCCH but not the whole encrypted message which is split and sent over multi-channel by MLSP® technology.
Same for metadata file: is sent over the network in bursts, separately from encrypted message body. No metadata extraction is possible at this level.
 
3. Core network level
 
The four-layer transport protocol stack of SMS (application, transfer, relay, and link) is used at this level and the transfer layer of this stack is the one which secure text message. GSM core network consist in Mobile switching center (MSC), Home location register (HLR), Authentication center (AuC), Visitor location register (VLR) and Equipment identity register (EIR), which are all vulnerable to network switch based interception, also known as SS7 interception or lawful interception. This kind of interception can be successfully performed only by law enforcement and homeland security agencies, by the help of network provider that allow monitoring hardware installation (SS7 boxes) at their core network based on Communications Assistance for Law Enforcement Act (CALEA). CALEA's purpose is to enhance the ability of law enforcement agencies to conduct lawful interception of communication by requiring that telecommunications carriers and manufacturers of telecommunications equipment modify and design their equipment, facilities, and services to ensure that they have built-in capabilities for targeted surveillance, allowing federal agencies to selectively wiretap any telephone traffic. CALEA covers mass surveillance of communications rather than just tapping specific lines and not all CALEA-based access requires a warrant. Generally, lawful Interception implementation is similar to the implementation of conference call. While A and B are talking with each other, C can join the call and listen silently.
 
At this network level, the main security vulnerability consist in lawful interception. XCrypt is taking advantage on GSM core network, sending both encrypted and non-interceptable text messages by using MLSP® technology. Core network protocols cannot be enforced as Um interface can. Actually there is no need to manipulate those protocols and transfer layers as long as message bursts that transit this part of the mobile network can be logically concatenated (fit together) by Port Addressing and decrypted only by "BParty" phone which run the same XCrypt application and by knowing the right password. By consequence, no text messages can be entirely intercepted by a third party that use CALEA - lawful interception. A few encrypted SMS bursts which are eventually intercepted by SS7 cannot lead by any means to SMS interception. Thus no private data will be collected by this method, phone user privacy being preserved peer-to-peer from "A-Party" to "B-Party" phone.
Let's face it: most of nowadays encryption solutions are taking care only on text itself, neglecting message metadata which are still sent on plain text over the network, due to network requirements. Law enforcement and other actors are taking advantage on this, collecting unencrypted metadata to characterize the encrypted data, metadata being this way a valuable source of information for them.
By using MLSP® technology on both Um and Core network levels, collecting unencrypted message metadata is not possible, thus no way to extract any additional info beside encrypted message.
It has long been said that it doesn’t matter how secure your organization, or personal information and assets, are if you connect them with third parties that are less secure. So take note: servers are third parties.
A real end-to-end encryption require no third parties involved on the way from "A-Party" to "B-Party" phone.
 
For maximum level of security and privacy, XCrypt does not require any Internet connection, third party servers or monthly subscriptions. All processes and protocols run locally on the phones (on Sandbox partition) providing this way not just a real end-to-end unbreakable encryption, but also non-interceptable messages by the reasons explained above.
XCrypt has been already implemented as standard on XCell Basic v3 Stealth Phones, both on Basic and Advanced versions.

Back in 2018, XCell Technologies has launched a new Stealth Phone series, based on legendary Nokia 3310 2017: XCell Basic v3 Stealth Phones. There are available both 2G and 3G global versions which are compatible with Canadian and Australian 3G mobile networks.
Advanced Nokia 3310 Stealth Phone have the following functions:

  1 - Call/SMS interception alert (active, passive and SS7 interception);
  2 - IMSI Change which is transforming the phone in a real sophisticated counterintelligence weapon. IMSI Change function does not require any Internet connection, third party servers or monthly subscription. This special function runs locally on the phone (Sandbox partition), being a unique function which no other phones offer at this time.

IMSI Change function allow user to change IMSI value (SIM registration number stored on the SIM card), by keeping the same phone number (MSISDN).

How does it work?
The phone will clone any SIM card inserted (please use only MNO SIM Cards) by using a Sandbox located app: IMSI Virtual Engine. Once cloned, the real SIM will be quarantined, being used instead a virtual SIM card which can change its IMSI by by generating valid IMSI’s. Please note that abusing this function can generate SIM network rejection (network dependent). Use it carefully.
IMSI Change does not work automatically, as IMEI change works. The user should launch IMSI Change every time when a new IMSI is needed, generating a new virtual IMSI and then exiting the application. The new generated IMSI will be used only for the next outgoing or incoming call. After that, the phone will return to original IMSI. If a new IMSI will be needed, the whole process should be repeated.
Please note that MSISDN (the phone number) will not change when using IMSI change function.
IMSI change function will transform your Nokia 3310 Stealth Phone in one of most powerful communications weapon: you will literally have a new SIM (IMSI) for every single phone call. Use it with precautions.

3 - cryptoTRACERⓇ, which is a function that can detect lawful interception performed by SS7 Boxes (aka Network Switch Based Interception);

4 - Sandbox
IMEI engine and other software components has been moved in a separate partition (Sandbox) in order to make them working faster and smoother. System restarting has been suppressed in case of any abnormal network characteristics (i.e. generated by IMSI Catchers/GSM Interceptors).

5 - Interception Instant Check
Once launched, the function will start checking both Active and Passive interception, step by step. Regarding interception performed with Active/Semi Active GSM Interceptors, the phone will check:
 
1.    BTS parameters
2.    RSSI
3.    Cell ID
4.    LAC
5.    ARFCN
6.    Ki retrieving attempts (ciphering key stored on the SIM card).
7.    Baseband attack attempts.
 
Regarding interception performed by Passive GSM Interceptors, the phone will check:
 
1.    Uplink.
2.    Downlink.
3.    Will ping HLR/VLR core network, computing network redundancy and abnormal ping delays.
4.    In the end, will generate a Network Security Rating.
 
6 - C1/C2 monitoring
By forcing cell reselection (C2 parameter), Active and Semi Active GSM Interceptors will force any cell phones to disconnect from home network and connect to the rogue BTS impersonated by the equipment. This is called also BCCH manipulation, being used by all modern GSM Interceptors. When launching this function, the phone will:
 
1.    Extract C1 value, from serving cell.
Will compute C2 value by using a special algorithm, the same used by any GSM network
2.    Will look for at least other 6 neighboring cell towers, ordered by RSSI value.
Will compare C1 to C2.
3.    Will trigger alert if no neighboring cells are found (a clear indication that a GSM Interceptor is active within area).
Will look for CPICH, RSCP and BCCH.
4.    Will display forced handover attempts (if any).
5.    Will display Channel lock fails (if any).

7 - Military grade SMS encryption. Please note that you need at least 2 units in order to use SMS encryption feature.

8 - Anti Interception: as long as phone is under surveillance by any means (no matter if IMSI Catcher, GSM Interceptor or SS7), voice calls and SMS will be blocked (both incoming and outgoing).

9 -  Real Location Spoofing: user can hide GSM location by selecting the farthest BTS which phone is connected to, avoiding this way triangulation procedures widely used by law enforcement for location tracking purposes. Will work both when stationary and on the move.

You see below actual pictures of special functions added to XCell Basic v3 Advanced Stealth Phone.

Moreover, XCell Technologies added on XCell Basic v3 Advanced Stealth Phone an absolutely new breed of secure SMS which is not just encrypted but use a brand new technology patented last month, which makes SMS also non-interceptable. This is a revolutionary innovation called Multi-Layer Security Protocol - MLSP®, developed and patented by XCell Technologies.
Taking advantage on GSM network architecture and SMS Transport Protocol, our SMS encryption technology is capable to send/receive encrypted and non-interceptable messages.
 
Please note that for exchanging encrypted messages you need at least 2 phones: sender phone will encrypt the message and receiver phone will decrypt the message.

MLSP® consist in:

1. Physical layer: encrypted text message.
The phone will encrypt text messages by using following protocols:
•    RSA
•    AES 256
•    Elliptic Curve (ECIES) 256
•    SHA256
•    Protected by ITSEC Evaluation level 3

2. Multi-layer routing and transport protocol. Encrypted SMS data is randomly segmentated and distributed in bursts by Application Port Addressing Technology, via discrete GSM channels which usually are not "listened" by mobile interception systems (IMSI Catchers, GSM Interceptors or StingRays), both in air interface (UM Interface in terms of GSM networks) and Abis, A and C-G mobile network interfaces. This way, SMS data which is usually sent over GSM Layer 1 (and widely intercepted on Layer 1) will be sent by using a combination of GSM Layer 1 and GSM Layer 2 (LAPDm). By consequence, no mobile interception systems (as GSM Interceptors) and lawful interception systems (SS7 interception also known as network switch based interception or interception by the help of network operator) will be able to intercept the whole message but only a few bursts which are encrypted anyway.

3. Metadata protection. Regular SMS metadata is not saved in a separate file (called a metadata file). XCrypt separate metadata and the data it describes (SMS encrypted text), sending metadata file in bursts over the network, by the same Port Addressing technology. Metadata is of little value without the data file (SMS) it relates too. At the same time, metadata makes the data more usable and therefore, more valuable. An encrypted text message with separate metadata file will reveal nothing about SMS sender and receiver.

XCell Technologies SMS encryption application use a groundbreaking multi-layer technology to protect SMS from being intercepted and decrypted. As a unique encryption application, beside strong military grade encryption, XCrypt use a brand new patented technology in order to send/receive encrypted messages: discrete GSM channels or Multi-Layer Security Protocol®. That will protect not just encrypted text messages but also metadata which is not encrypted.
 
You can download the whole PDF document regarding MLSP@ technology and XCrypt applications, by clicking on image below: