Researchers Dennis Hofheinz and Eike Kiltz (CWI in Amsterdam) received the Best Paper Award from the IACR Eurocrypt 2009 conference on 29 April in Cologne. This is one of the leading international conferences in cryptography. The mathematicians won the price for their article "Practical Chosen Ciphertext Secure Encryption from Factoring”, which addresses a new mechanism for Internet security. Possible future applications of their research are better security of web browsers, e-mail, online shopping and online banking.
Secure Internet connections (marked by "https" in the URL), for example used in electronic banking, are often based on the RSA encryption system from the 1970's. This system is part of all web browsers and therefore there are hundreds of millions of copies in circulation. The security of RSA is the fact that the mathematical problem of factorization - the dissolution of integers into prime numbers – is very difficult to put into practice: the factorization of large numbers is extremely intensive.
It is however not clear whether there may be a hazardous 'backdoor' open in the version of RSA which is now used worldwide, or, to speak in mathematical terms: if the crack is really equivalent to factoring. Hofheinz and Kiltz have invented a variation on RSA which is also based on the factorization problem, almost as efficient as RSA, with which one can mathematically prove that the highest security level – ‘chosen ciphertext security' - is achieved. This solved a major problem, which has been researched by cryptographers since the 1980’s. The article of both CWI researchers was selected from over two hundred entries as ‘interesting cryptographic research’.
The research is co-financed by the NWO-Veni grant of Dennis Hofheinz and the PASC project Sentinels, a research program of STW, NWO and the Ministry of Economic Affairs.