Linear Cryptanalysis of DES - New Developments by Matsui

[Bruce Schneier]

On Jan. 27, at the Japanese Conference on Cryptography and Information 
Security, Mitsuru Matsui of Mitsubish presented a known plaintext
attack on the full 16-round DES.  It requires  2^43 plaintext-ciphertext
pairs, and breaks the scheme in 50 days on 12 HP9735 workstations.

I have absolutely no more information at this point.  I will post again
when I know something else.

Bruce