LASH, the lattice-based hash function designed by Kamel Bentahar, Dan Page, Markku-Juhani O. Saarinen and Nigel Smart has been broken into tiny little pieces. A septumvirate of authors (Scott Contini, Krystian Matusiewicz, Josef Pieprzyk, Ron Steinfeld, Jian Guo, San Ling, and Huaxiong Wang) have submitted the following devastating analysis of LASH-x to FSE 2008:

• Preimages for LASH-x in about 2^0.36x hash evaluations (and memory).
• Collisions for LASH-x in about 2^0.57x work (and storage). LASH-160’s maximum security level thus effectively is about 58 bits, for LASH-256 we get 93 bits.
• Long-message attacks using lattice reduction techniques
• LASH is not a pseudo-random function (control 1 byte of input and distinguish the output from random with probability 2^{-8})
• A TMTO attack on the final compression function working in about O(x2^x/4) time and memory
• Heuristics for a CVP attack against LASH-160 (using NTL‘s BKZ implementation)

The pre-image and collision attacks presented in the paper exploit the specific fact that LASH uses an all-zero IV, however the authors also demonstrate that tweaking the hash function by changing the IV will not help much. An extended version of the article is available on the IACR’s ePrint server.
Update 2007-12-03: as correctly pointed out in a comment by random, this paper has only been submitted to FSE 2008. It is not clear yet whether it is accepted or not, since notifications of acceptance will only be sent out on December, 10th, 2007. Sorry for the confusion!
Update 2007-12-18: The list of accepted papers for the FSE 2008 is public. The LASH paper has been accepted.

Michael Vielhaber presents an interesting result against a reduced version of the eSTREAM submitted cipher Trivium in a paper on the IACR ePrint archive. By reducing the key setup from 4 full rounds (1152 clock cycles) to two cycles (576 cycles) he is able to mount a chosen IV algebraic attack using a total of 2^6 chosen IV resyncs. This reduced version is called ONE.FIVIUM by him. The impact of the attack against ONE.FIVIUM that 47 of the 80 key bits are claimed to be determined with probability 1 by this attack. The write up needs polishing but most of the results indeed mostly check out. Unfortunately the method by which he arrived at these results is (in my opinion, at least) only superficially described. I strongly suspect this paper is intended to mark a claim. Further results against a clock setup with more cycles are to be expected. Trivium is living dangerously.If you want to check out Michael Vielhaber’s results yourself, I have written Python code for just that. My colleague Andrey Pyshkin initially confirmed the 6 out of the first 7 approximations listed in the table, aidatest.py checks all of them. Below is the output of 256 runs.

approx. for key bits [1] was correct 256 out of 256 times
approx. for key bits [2, 65] was correct 256 out of 256 times
approx. for key bits [3, 66] was correct 0 out of 256 times
approx. for key bits [4] was correct 256 out of 256 times
approx. for key bits [5] was correct 256 out of 256 times
approx. for key bits [6] was correct 256 out of 256 times
approx. for key bits [8] was correct 256 out of 256 times
approx. for key bits [9] was correct 256 out of 256 times
approx. for key bits [11] was correct 256 out of 256 times
approx. for key bits [14] was correct 256 out of 256 times
approx. for key bits [16] was correct 256 out of 256 times
approx. for key bits [17] was correct 256 out of 256 times
approx. for key bits [19] was correct 256 out of 256 times
approx. for key bits [25] was correct 256 out of 256 times
approx. for key bits [26] was correct 256 out of 256 times
approx. for key bits [27] was correct 256 out of 256 times
approx. for key bits [36] was correct 256 out of 256 times
approx. for key bits [38] was correct 256 out of 256 times
approx. for key bits [39] was correct 256 out of 256 times
approx. for key bits [55] was correct 256 out of 256 times
approx. for key bits [56] was correct 256 out of 256 times
approx. for key bits [57, 63] was correct 256 out of 256 times
approx. for key bits [59, 65] was correct 256 out of 256 times
approx. for key bits [60, 66] was correct 256 out of 256 times
approx. for key bits [61] was correct 256 out of 256 times
approx. for key bits [62] was correct 256 out of 256 times
approx. for key bits [63] was correct 256 out of 256 times
approx. for key bits [64] was correct 256 out of 256 times
approx. for key bits [65] was correct 256 out of 256 times
approx. for key bits [66] was correct 256 out of 256 times
approx. for key bits [67] was correct 0 out of 256 times
approx. for key bits [68] was correct 0 out of 256 times
approx. for key bits [15] was correct 256 out of 256 times
approx. for key bits [18] was correct 256 out of 256 times
approx. for key bits [20] was correct 256 out of 256 times
approx. for key bits [23] was correct 256 out of 256 times
approx. for key bits [30] was correct 256 out of 256 times
approx. for key bits [32] was correct 256 out of 256 times
approx. for key bits [33] was correct 256 out of 256 times
approx. for key bits [35] was correct 256 out of 256 times
approx. for key bits [58] was correct 166 out of 256 times
approx. for key bits [21] was correct 256 out of 256 times
approx. for key bits [22] was correct 256 out of 256 times
approx. for key bits [10] was correct 115 out of 256 times
approx. for key bits [12] was correct 141 out of 256 times
approx. for key bits [58] was correct 256 out of 256 times
approx. for key bits [69] was correct 256 out of 256 times