New Developments in Cryptography

Wired reports in this article of a recent advance in deployed cryptography by Google.

Last summer the NSA published an advisory about the need to develop and implement new crypto algorithms resistent to quantum computers. Indeed if and when quantum computers will arrive, they will be able to crack easily some of the most fundamental crypto algorithms in use, like RSA and Diffie Hellman. The development of quantum computers is slow, still it continues and it is reasonable to expect that sooner or later, some say in 20 years, they will become reality. Also the development of new crypto algorithms is slow, so the quest for crypto algorithms resistant to quantum computers, also called post-quantum crypto, has already been going on for a few years.

Very recently Google has announced the first real test case of one of these new post-quantum algorithms. Google will deploy to some Chrome Browsers an implementation of the Ring-LWE post-quantum algorithm. This algorithm will be used by the chosen test users, to connect to some Google services. Ring-LWE will be used together with the current crypto algorithms adopted by the browser. Composing the current algorithms with Ring-LWE will guarantee a combined level of security, that is the minimum level of security is that of the strongest algorithm used in the combination. It should be noted that Ring-LWE is a much more recent crypto algorithm compared to the standard ones, and its security has not been established yet to a comparable level of confidence.

If the level of security will not decrease and hopefully just increase, it has to be seen how it will work in practice in particular for performances.

For modern cryptography this two-year Google’s project could become a cornerstone for the development and deployment of post-quantum algorithms.