Telecom
Hackers Could Decrypt Your GSM Phone Call
Researchers have discovered a flaw in the GSM standard used by AT&T and T-Mobile that would allow hackers to listen in.
Researchers from BlackBerry at DefCon security conference in Las Vegas, USA, presented an attack that can intercept GSM calls as they’re transmitted over the air and decrypt them to listen back to what was said.
And the vulnerability has been around for decades.
Most mobile calls around the world are made over the Global System for Mobile Communications standard; in the US, GSM underpins any call made over AT&T or T-Mobile’s network.
Regular GSM calls aren’t fully end-to-end encrypted for maximum protection, but they are encrypted at many steps along their path, so random people can’t just tune into phone calls over the air like radio stations.
The researchers found, though, that they can target the encryption algorithms used to protect calls and listen in on basically anything.
“GSM is a well documented and analyzed standard, but it’s an aging standard and it’s had a pretty typical cybersecurity journey,” says Campbell Murray, the global head of delivery for BlackBerry Cybersecurity.
“The weaknesses we found are in any GSM implementation up to 5G. Regardless of which GSM implementation you’re using there is a flaw historically created and engineered that you’re exposing.”
The problem is in the encryption key exchange that establishes a secure connection between a phone and a nearby cell tower every time you initiate a call.
This exchange gives both your device and the tower the keys to unlock the data that is about to be encrypted. In analyzing this interaction, the researchers realized that the way the GSM documentation is written, there are flaws in the error control mechanisms governing how the keys are encoded. This makes the keys vulnerable to a cracking attack.
“It’s a really good example of how the intention is there to create security, but the security engineering process behind that implementation failed.”
As a result, a hacker could set up equipment to intercept call connections in a given area, capture the key exchanges between phones and cellular base stations, digitally record the calls in their unintelligible, encrypted form, crack the keys, and then use them to decrypt the calls.
The findings analyze two of GSM’s proprietary cryptographic algorithms that are widely used in call encryption—A5/1 and A5/3.
The researchers found that they can crack the keys in most implementations of A5/1 within about an hour. For A5/3 the attack is theoretically possible, but it would take many years to actually crack the keys.
“We spent a lot of time looking at the standards and reading the implementations and reverse engineering what the key exchange process looks like,” BlackBerry’s Murray said.
“You can see how people believed that this was a good solution. It’s a really good example of how the intention is there to create security, but the security engineering process behind that implementation failed.”
The researchers emphasize that because GSM is such an old and thoroughly analyzed standard, there are already other known attacks against it that are easier to carry out in practice, like using malicious base stations, often called stingrays, to intercept calls or track a cellphone’s location.
Additional research into the A5 family of ciphers over the years has turned up other flaws as well. And there are ways to configure the key exchange encryption that would make it more difficult for attackers to crack the keys. But Murray says that the theoretical risk always remains.
Short of totally overhauling the GSM encryption scheme, which seems unlikely, the documentation for implementing A5/1 and A5/3 could be revised to make key interception and cracking attacks even more impractical. The researchers say that they are in the early phases of discussing the work with the standards body GSMA.
The trade association said in a statement to WIRED that, “Details have not been submitted to the GSMA under our coordinated vulnerability (CVD) programme. When the technical details are known to the GSMA’s Fraud and Security Group we will be better placed to consider the implications and the necessary mitigation actions.”
Though it may not be that surprising at this point that GSM has security issues, it’s still the cellular protocol used by the vast majority of the world. And as long as it’s around, real call privacy issues remain, too.
Meta may shut down its Facebook and Instagram services in Nigeria in protest against the substantial fines imposed by multiple government agencies.
The tech giant has been ordered to pay nearly $300 million in fines in Africa’s most populous nation, following regulatory demands which Meta described as “unrealistic.”
In July 2024, the Federal Competition and Consumer Protection Commission (FCCPC), imposed a $220 million fine on Meta for allegedly discriminatory and exploitative practices against Nigerian consumers.
The commission stated that Meta had failed to engage a Data Protection Compliance Organisation and had not submitted a Nigeria Data Protection Regulation audit report for two consecutive years.
Similarly, the Advertising Regulatory Council of Nigeria (ARCON), demanded $37.5 million over unapproved advertising, while the Nigerian Data Protection Commission (NDPC), announced a $32.8 million fine for an alleged data privacy breach.
Meta challenged the decisions at the Federal High Court in Abuja but was unsuccessful, as the court upheld the fines in a ruling delivered last week.
The court directed the company to comply with payment by the end of June, but Meta has indicated it may not do so, according to the BBC.
“The applicant may be forced to effectively shut down the Facebook and Instagram services in Nigeria in order to mitigate the risk of enforcement measures,” the company stated in court documents.
Responding to the NDPC’s assertion that Meta’s data processing could expose Nigerian users to health and financial risks, the company said the agency had failed to “properly interpret the laws guiding data privacy.”
As the Premier League season enters its final stretch, MTN Nigeria is set to stage simultaneous watch parties in Abuja and Uyo on Sunday, May 4, giving football fans a shared space to experience the highs and lows of matchday.
The events, scheduled for Farm City in Wuse and Pyramid Lounge & Grill in Uyo, are expected to attract large turnouts as MTN continues to deepen its connection with football audiences nationwide.
The line-up for the day includes four Premier League fixtures, culminating in a marquee showdown between Chelsea and Liverpool. Earlier games such as Brentford vs Manchester United, Brighton vs Newcastle, and West Ham vs Tottenham will round out a packed viewing schedule. With top four ambitions, title races, and European dreams on the line, the fixtures promise high-stakes drama and entertainment.
MTN’s EPL watch parties have grown into a recurring highlight for fans who want more than just a screen, they want atmosphere. This weekend’s events will feature expansive screen setups, branded fan zones, and side attractions including live trivia and merchandise giveaways.
For MTN, the activations represent an opportunity to tap into the communal spirit of football, a sport that unites Nigerians across regions and loyalties. The brand’s involvement in football has steadily evolved from sponsorship to full-scale experiences, allowing it to build affinity with youth audiences and sports lovers alike.
In recent years, MTN has emerged as a key driver of fan engagement through its partnership with SuperSport and broader investment in Nigeria’s football ecosystem. These dual-city events reflect that strategy in motion, bringing the Premier League closer to the streets and ensuring fans are not just spectators, but participants in the global game.
With anticipation running high and bragging rights on the line, Sunday’s watch parties are shaping up to be a celebration of sport, identity, and the power of community on and off the pitch.
Telecommunications services disrupted in Kogi State have resumed following a resolution of the dispute between MTN Nigeria and the state government, the Association of Licensed Telecoms Operators of Nigeria (ALTON) has said.
Gbenga Adebayo, chairman of ALTON, told TVC News that the issues that led to the shutdown of telecom masts in the state, primarily affecting MTN, had been addressed, paving the way for service restoration.
TVC News earlier reported that businessmen and women were counting their losses as they suffered the impact of a shut down of telecommunication service in Kogi State
Over the past two weeks, telecoms connectivity had been erratic, with competing brands experiencing glitches, particularly in the Lokoja metropolis.
The State government suspended the operations of some telecom services citing unpaid taxes and fibre-related dues.
The shutdown stemmed from a compliance dispute between MTN and the Kogi State Utility Infrastructure Management and Compliance Agency, which accused the telecom giant of violating operational rules and under-declaring the extent of its optic fibre network coverage in the state.
Fines: Meta Threatens to Shut Down Facebook, Instagram in Nigeria
History as TVC News Unveils Nigeria’s First AI-Powered News Anchors
Court Rejects Bid to Stop CBN from Using e-Naira Trademark
MRA Flags AI Concerns ahead of Press Freedom Day Today
NITDA, RHI, Commission IT Community Centre in Ibadan
E-Financial3 days agoCBN Slams ₦250m Fine on Paystack Over Zap Wallet Operations
General News3 days agoNITDA Inaugurates Start-up Consultative Forum
Telecom2 days agoSterling Bank Introduces AlwaysOn, Offering Nigerians Up to ₦1 Million Monthly
Telecom3 days agoGBB Reaffirms Commitment to Driving Public Sector Innovation @ the 5th Public Service Innovation Competition Awards
General News3 days agoNFIU Alerts Nigerians of Rising Ponzi Schemes, Unregulated Crowdfunding Scams
News3 days agoFirm Warns Against AI Password Generation @ World Password Day
Telecom2 days agoBanks Settle ₦160Bn USSD Debt to Telcos, Ending Five-Year Dispute
Telecom3 days ago5 tips to start taking digital payments as a business in Africa