More than a quarter century after its introduction, the failed rollout of hardware deliberately backdoored by the NSA is still having an impact on the modern encryption debate.
Known as Clipper, the encryption chipset developed and championed by the US government only lasted a few years, from 1993 to 1996. However, the project remains a cautionary tale for security professionals and some policy-makers. In the latter case, however, the lessons appear to have been forgotten, Matt Blaze, McDevitt Professor of Computer Science and Law at Georgetown University in the US, told the USENIX Enigma security conference today in San Francisco.
In short, Clipper was an effort by the NSA to create a secure encryption system, aimed at telephones and other gear, that could be cracked by investigators if needed. It boiled down to a microchip that contained an 80-bit key burned in during fabrication, with a copy of the key held in escrow for g-men to use with proper clearance. Thus, any data encrypted by the chip could be decrypted as needed by the government. The Diffie-Hellman key exchange algorithm was used to exchange data securely between devices.