Questions tagged [gsm]

a standard developed by the European Telecommunications Standards Institute for the second generation of digital cellular networks, used by mobile phones. It is the default global standard for mobile communications.

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How is the stream cipher key shared on GSM?

I read that phones encrypt communication (GSM as implemented in 2G,3G..) - particularly voice as SMS are unencrypted - using a stream cipher. Symmetric Stream ciphers use the flip-flop machinery to ...
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Reporting dual sim phone stolen [closed]

A burglar took my phone so I reported it to the police and phone company to blacklist it. They only asked for the first IMEI even though the phone has two IMEI since it can accomodate two SIMs. The ...
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How to calculate Millenage OPc value while OP stored in HSM?

ETSI TS 135 206 defines the specification of MILENAGE algorithm which is an authentication algorithm for mobile networks. It defines 'OPc' as below: a 128-bit value derived from OP and K and used ...
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Can a wifi Access Point be reconfigured to receive other radio signals?

Say we have a remote transmitter that is not connected to a wifi router (neither wirelessly nor by cable), but which transmits information using electromagnetic waves. Examples include walkie-talkies, ...
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Security assessment of a legacy SSL/TLS implementation on an IoT device

I am doing a security assessment on the communication security of a legacy IoT device. The objective is to assess and find security gaps in the current design/implementation. The mode of assessment is ...
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Is inputting credit card numbers over a mobile phone secure?

I'm in the UK. In order to top up a pay-as-you-go SIM card, I had to first ring the mobile network to associate my bank card with the SIM before asking them to credit £10 to it (future top-ups don't ...
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4 votes
3 answers
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2-step authorization (using SMS) is less secure than having 2-factor disabled at all!

I've been thinking about this subject, and found paradoxical fact. Having a service that has 2-step authorization using SMS might become more harmful and open vulnerability hole (read SMS can be ...
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GSM encryption/decryption algorithms

I have seen around the internet devices like this: https://www.cryptophone.de/ and software that reinforce the security on cellphones. My question is simple, since the cellphones use A5/1, A5/2, A5/3 ...
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A SIM module-based security system and radio signal interruptions

I would like to setup a simple alarm system using something like a Raspberry Pi or Arduino, some sensors, and a SIM module to send me an alarm when an intrusion is detected. If I were dealing with an ...
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2 votes
1 answer
956 views

What is more safe: 3g/4g or public wifi?

The scenario is: John is out of home and, using his smartphone, he need to send some messages from Whatsapp, use Facebook's app and do some bank operations. Since I have read this and this topics, I'...
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Getting called from hidden caller ID, what are the dangers if I answer?

My girlfriend has been getting calls on her iPhone from a hidden caller ID for several days in a row now. She has not answered any of them because we figured it can't be anything good if it's hidden. ...
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What are the dangers of using 3g/4g in smartphones?

Since we should always avoid public networks, is there some sort of attack that intercept my online activity or steal passwords when I'm using 3g/4g? If exists, how I can protect myself from this type ...
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Who: phone manufacturers, GSM operators or OS-creators (or whoever) should care that our mobiles do not to connect to rogue GSM towers?

Which one in this chain should be blamed for not taking care of security: Phone manufacturers, GSM operators, SIM card manufacturers or OS systems (Android, iOS, etc..) to protect our phones from ...
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Do mobile phones automatically connect to spoofed cellular tower antenna?

I was told that an attacker is able to create a fake cellular tower antenna imitator near your mobile phone, and your phone will automatically connect to it, whether that antenna has an encrypted ...
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View packets of whatsapp?

I start doing a research about what's actually delivered from some android applications (such as telegram or whatsapp) outside to the world. I do it in the following mediums: 1. Wifi 2. GSM It ...
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How to retrieve the Ki value of sim card?

I was wondering is there any way to catch the Ki value in the SIM card by any coding? Is there a tool for that? NOTE: Ki, only exist in SIM (Mobile Station) and BSC database. It won't be transmitted ...
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GSM - Implementing Cipher Mode Command on YateBTS

I've been studying on Yate & YateBTS source code for a while, and I was wondering why there is no ciphering mode implementation in the source!? I use the combination of BladeRF x40 FPGA and ...
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How are USSD messages used and who could send them?

Some illegal ads started showing up on my Android phone as message boxes recently. They are said to be "USSD messages" in an app recording notifications (com.evanhe.nhfree). There is a Wikipedia ...
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Why doesn't public or open WiFi use unique encryption for each client (like GSM)?

I wanted to ask a networking security question about open or public WiFi. This question is not a duplicate of Why isn't open WiFi encrypted? Reading about cellular networks I found out that cellular ...
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Detecting GSM activity [closed]

Is it possible to detect the GSM usage activity using SDR? I know that it's possible to do this using EMF meter, for example. What about SDR? Radius of the range: 30-40 meters P.S. ..GSM activity - ...
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Device location in LTE/GSM packets? [closed]

I'd like to know if any of the LTE or GSM packets have the GPS coordinates of a given device or any information about its geolocation. I mean, there must be a way to locate devices (maybe ...
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Can location/owner of mobile phone be identified

Let's say someone uses GSM network mobile phone to pursue his/her online activities on social networking platforms. The mobile phone is Android and all online activities are done through a VPN tunnel (...
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Why does cellular communication protocols use A5 or KASUMI and not AES or 3DES or RSA

Why does cellular communication protocols use A5 or KASUMI and not AES or 3DES or RSA? I have read that A5 is not that secure, is this the case? Are A5 or KASUMI used anywhere else? Why only in ...
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Android as GSM basestation

Is that possible to turn an Android GSM into a basestation? For example, if it can send and receive data then it can emulate that even if it's for an only device, if it was that simple there were no ...
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What phone would be most private and what aspects to consider? [closed]

I want to change my phone and I would not use it for anything than calling and messaging. I would be happy to have phone the most private friendly and secure against any type of information withdraw ...
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1 answer
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Is it true that smartphones could get compromised via their baseband chip?

I read about this here. If I understand this correctly, it states that a smartphones could get compromised via it's baseband chip and it's (potentially) unsafe and closed-source firmware. I also ...
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3 votes
2 answers
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Can SIM card be locked to the specific equipment?

I'm curious if SIM card can be "personalized" to operate only in the specified mobile equipment in addition to usual PIN security. So the SIM extracted from "legitimate" phone and placed into ...
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3 votes
1 answer
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Why is callerID spoofing not possible when using short codes?

The question is already in the headline: Why is callerID spoofing not possible when the destination number is a short code? Here for example the answer to the question if callerID spoofing is still ...
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-1 votes
2 answers
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IMSI catcher vs MiTM attack

On reading about IMSI catchers, it is almost always mentioned together with MITM attacks, i.e. as if IMSI catchers are same as MITM. But from my understanding, IMSI catchers and MITM are not the same ...
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8 votes
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GSM encryption suppression

The following papers explain that it is possible to suppress the encryption (or downgrade) in GSM using faked messages: https://pdfs.semanticscholar.org/3a86/4f867aadaea449623ddbf288c18815e7eb00.pdf ...
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2 votes
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create GMS base station with mobile devices [closed]

I would like to create my own GSM network (base station with mobile devices connected to each other) and having voice/sms services. Something like demonstrated here: https://evilsocket.net/2016/03/31/...
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Catch incoming SMS/Calls in a fake GSM Network

I am currently working on a Project where I am doing a downgrade attack from LTE to GSM. I am using OpenLTE and OpenBTS for creating the fake base stations. When the phone connects to the fake GSM ...
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3 votes
1 answer
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How to perform RACH attacks on GSM mobile networks?

I am studying various vulnerabilities on GSM networks and would like to know what hardware and software are needed to test such vulnerabilities.
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2 votes
1 answer
275 views

What is the state of 3G data cryptography?

A client of my company is currently using a solution where they've invented a UDP protocol that communicated with no TLS over regular 3G in small embedded devices. Their cellular provider, KORE, ...
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3 votes
1 answer
159 views

As a mobile carrier, how do you defend against mobile attacks like Stingrays?

I would like to know what ways there are (if any) to defend against Stingrays and similar interception if you are a mobile carrier and have full control of the base stations and SIM cards? Can a SIM ...
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Does old SIM-cards have the same security as new one?

As I am using an old (10-15 years) SIM-card, I was asking myself if the hardware and software on the sim-card is equivalent to the newer sim-cards. Are the old-sim-cards (10-15years) the same as the ...
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Encryption and Decryption in WEP protocol [duplicate]

What is the role of Integrity Check Value in Wireless Equivalent Privacy? Why initialization Vector is sent as a clear message where as Integrity Check Value is sent as a cipher message?
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What information is being transmitted to the carrier when making a call on a GSM network?

I was wondering how carriers could track your calls and phone. I know that that there are a few things that are sent to the cell towers (and then to the carrier if it is logging the information) when ...
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PDU: SMS-DELIVER direct from a GSM Modem

My understanding of the SMS-DELIVER/SMS-SUBMIT is that when Bob wants to send a text on the GSM the following happens... Bob submits a request to send a short message to a short message service ...
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call spoofing online server

My friend has an app, in which he dials my number, and on my mobile, I see my own number calling me. He basically spoofs my number. He claims that there are online call services via which we can do ...
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6 votes
4 answers
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Spoof coordinates sent by a GPS tracker device

Is there any way to change the GPS coordinates with fake ones? Eg. make a GPS tracker with a GSM modem for car tracking report fake coordinates for a short period of time before returning back to ...
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2 votes
0 answers
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End-To-End encrypted calls over GSM transport (not data / VoIP)

As the issue stands, it should be (or could be) possible, to encrypt voice, that's being passed through GSM voice call in such way, so that it's end-to-end encrypted. Ideally in form similar to what ...
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1 answer
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Phone conversations being recorded and played back [duplicate]

Regarding below post from 2014, I have the exact same problem with every call I make to Lebanon. How do I stop this? Is it a bug? I have factory reset my phone and it's still happening. My wife ...
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2 votes
1 answer
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GEA3 direction clarification

GEA3 (and 4) stands for GPRS Encryption Algorithm. It's specified in 3GPP TS 55.216 (at least used to, until some idiot forced them to hide it because of "export restrictions" or some crap like that). ...
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Difference between "Unknown" and "Hidden" Caller ID

I remember the times when I had an old Nokia phone as my main; there was some weird behaviour with Caller ID which was strange for me. When somebody with subscription to "Hide your number" service ...
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In mobile, can "Early Media" be sent from the phone?

Early Media, aka in-band information, is sent from the network to the calling phone in some circumstances, to provide alternative tones or extra information about the status of the call. In GSM this ...
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SS7 exploit on the wiretapping part

Wondering if there are info/source code/guide on the SS7 wiretapping part (SMS interception). I had a look on the track any mobile by a German researcher, and on PTsecurity about how the structure ...
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Best way to keep cell day to day phone calls private - is VOIP better?

This question is about preventing eavesdropping by hackers, thieves, or other smart people collecting information for shady purposes. Is it better to buy a smartphone and install a VOIP service on it ...
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Is there a way to uniquely identify a mobile device through packet sniffing?

I need to uniquely identify a mobile device using the "ping" packets that it transmits to cellular towers regularly, in an area of interest by installing a packet sniffer at that location? I only need ...
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4 votes
1 answer
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Capturing text messages on the fly

Suppose your phone is not connected to any network. You are sitting in a cafeteria with 50 other people, everyone is communicating to each other via text messages. Is it possible through any device or ...
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