Published on *Computer Science Department at Princeton University* (http://www.cs.princeton.edu)

Recently Adleman has shown that a small traveling salesman problem can

be solved by molecular operations. In this paper we show how the same

principles can be applied to breaking the Data Encryption Standard

(DES). Our method is based on an encoding technique presented in

Lipton. We describe in detail a library of operations which are useful

when working with a molecular computer. We estimate that given one

arbitrary (plain-text, cipher-text) pair, one can recover the DES key

in about 4 months of work. Furthermore, if one is given cipher-text,

but the plain text is only known to be one of several candidates then

it is still possible to recover the key in about 4 months of

work. Finally, under chosen cipher-text attack it is possible to

recover the DES key in one day using some preprocessing.

**Links**

[1] http://www.cs.princeton.edu/research/techreps/author/273

[2] http://www.cs.princeton.edu/research/techreps/author/403

[3] http://www.cs.princeton.edu/research/techreps/author/381

[4] ftp://ftp.cs.princeton.edu/techreports/1995/489.ps.gz