Matsui-san Attack

[buckley at wti.com]

]> A bigger problem is that PEM uses DES rather than IDEA.  I just learned
]> of a new attack by Mitsuru Matsui of Mitsubishi that requires 2^43
]> *known* plaintexts, not chosen ones.  The note I received says that it
]> ``breaks the scheme in 50 days on 12 HP9735 workstations''.  This was
]> presented last week at the Japanese Conference on Cryptography and
]> Information Security.

50 days on 12 HP9735 = 600 days on a single HP9735
The 735 has a pretty fast Mflop rating (compared to Sun, IBM, SGI, PC, and
Macs).  Using a comparable breaker on the average machine, it is going
to take two years to "break the scheme".
That leaves two years to create stronger/tighter strategies.