The Great Hash Bakeoff: Infosec bods cook up next-gen crypto
Take a serverful of hash, add salt, hold the rainbow
Cryptographers are limbering up for a competition aimed at developing a next-generation password hash to create a better means for websites to store users' login credentials.
In total 24 submissions have been made to the Password Hashing Competition. Cryptographers will now test the effectiveness of the two dozen entrants by attempting to break them over the next 12 months or so before the competition closes.
The exercise seeks to identify new password hashing schemes that are suitable for widespread adoption as well as raising the profile of the issue and fighting against bad practices, such as storing passwords in plain text or not salting hashed passwords, as the competition website explains:
The Password Hashing Competition (PHC) is an effort organized to identify new password hashing schemes in order to improve on the state-of-the-art (PBKDF2, scrypt, etc.), and to encourage the use of strong password protection. Applications include for example authentication to web services, PIN authentication on mobile devices, key derivation for full disk encryption, or private keys encryption.
The PHC is being put together by a group of individuals, not an industry-recognised standardisation body. It might be that the competition throws up entrants who later become candidates for a standard but this is far from a given. Experts on the PHC panel include Matthew Green of Johns Hopkins University and Marsh Ray of Microsoft.
The competition is a marathon and not a sprint, explained Per Thorsheim, an independent security consultant and founder of the well regarded Passwords conferences.
"This competition is organised by Jean-Philippe Aumasson, known Swiss cryptographer and author of BLAKE, which was one of five finalists for the NIST SHA-2 competition," Thorsheim told El Reg.
"Submissions were due by 1 April, and now everybody is hard at work attacking all submissions in every way possible. The current timetable says that a winner will be selected in Q2 2015. Until then there will talks, conferences, mailing lists, meetings and whatnot."
One of the two dozens entries for the competition has already created a bit of a buzz on the interwebs. Researchers at New York University have developed a scheme called PolyPassHash for interlinking the representation of password hashes.
The idea is that instead of being able to use a rainbow table of the password hashes of common passwords or brute force tactics to recover passwords, attackers would be faced with the far trickier business of being obliged to crack groups of passwords together to get anywhere.
Hashing algorithms convert information into a shortened "message digest", via a one-way function that ought to make it impossible to recover the original information. Done successfully, the technology should thwart attempts to generate an identical digest from two different blocks of input data.
Hashing techniques are used in digital signatures, verifying that the contents of software downloads have not been tampered with, and many other cryptographic applications. ®