Update below.

The Next Web reports: A team of researchers from Cambridge University say they have found evidence that a Chinese-manufactured chip used by US armed forces contains a secret access point that could leave it vulnerable to third party tampering.

The researchers tested an unspecified US military chip — used in weapons, nuclear power plants to public transport – and found that a previously unknown ‘backdoor’ access point had been added, making systems and hardware open to attack, the team says.

Cambridge University researcher, Sergei Skorobogatov, explains:

We scanned the silicon chip in an affordable time and found a previously unknown backdoor inserted by the manufacturer. This backdoor has a key, which we were able to extract. If you use this key you can disable the chip or reprogram it at will, even if locked by the user with their own key.

This particular chip is prevalent in many systems from weapons, nuclear power plants to public transport. In other words, this backdoor access could be turned into an advanced Stuxnet weapon to attack potentially millions of systems. The scale and range of possible attacks has huge implications for National Security and public infrastructure.

While the initial research is a concern, a number of question marks remain over the findings before further conclusions can be drawn.

It is unclear if the access point is isolated to the chip that was tested or whether Skorobogatov and his colleagues have stumbled upon a larger trend. Likewise, it remains possible that the modified back door access could have been created by the US armed forces themselves.

Update: Robert David Graham says that while the Cambridge researchers “did find a backdoor in a popular FPGA chip, there is no evidence the Chinese put it there, or even that it was intentionally malicious.” He provides a detailed technical analysis explaining how he reaches this conclusion.