MUMBAI: An initial probe by EY into an alleged breach of Reliance Jio Infocomm’s customer base has showed that all of the telco’s apps and sites were secure and that the breach, if any, could have been at the external vendors’ end.People familiar with the matter said Jio had roped in consultancy EY to investigate the alleged data breach that was revealed on Sunday night by tech website FoneArena , which claimed that data of nearly 120 million Jio users had been leaked on an independent site named magicapk.A senior official in ministry of IT and electronics said Jio had reported the data breach incident to Cert-In, the ministry agency that tracks computer security. Cert-In will look into the matter while Jio is doing its own investigation. According to the people, Jio has also filed an FIR with the cyber crime cell of Navi Mumbai Police on Monday. Both EY and Jio did not respond to ET’s queries sent on Monday.On Sunday night, Jio said it was probing the report. The telco, though, said this was an “unverified” and “unsubstantiated” claim. Jio said it had informed law enforcement agencies about the claims of the website and would follow up with “strict action,” while assuring subscribers data was safe.FoneArena’s report has once again brought data security on telecom networks into focus. Carriers handle sensitive data and with many rolling out their payment banks, customer details become that much more fragile.“I think this (data breach) is a real threat all of us live with around the world and certainly in India,” Gopal Vittal , CEO (India & South Asia), Bharti Airtel , told reporters on Monday.“It’s not just telcos; it’s in banks and credit card companies. We try and do what we can to protect and ensure our systems are secure. The thing we value the most is customer privacy. We take that very seriously. This is what keeps us awake through the night,” he said.Carriers have been on an alert since a spate of ransomware attacks had hit companies across sectors. According to a study by industry body Assocham and research firm EY, mobile fraud is an area of great concern as 40-45% of financial transactions are via mobile devices. This threat will only grow as 60-65% financial transactions will be via mobile devices this year.“Telcos, with their digital wallets, could soon become the biggest banks. The onus is on them for any security breach. The IT ministry has to come up with more appropriate laws that prevent slips when technologies are changed,” said Venkat Nippani, partner IT, risk and cyber security, Grant Thornton India LLP.