Bruce Schneier may be correct about NSA's views, but I think the NSA gives itself too much credit. There was another very significant event in the 1970's which IMO played at least as much of a role in the increased interest in cryptography as the DES. This is, of course, the invention of public-key cryptography. I know that my own interest in crypto can largely be traced to the Scientific American column by Martin Gardner in which he introduced the RSA system (along with the famous RSA-129 number which was just factored). PK crypto combines simplicity with surprise to produce results which attracted a lot of attention and interest. In comparison, the development of DES was of relatively little interest outside of the few specialists in the field. I would suggest that PK crypto did more to attract attention to cryptography and to lure people to the field than did DES. If you look at the papers in the crypto conference proceedings you will see a number on cryptanalysis of DES and on DES-like systems, especially in the early days; but there are generally at least as many on PK and related ideas such as zero-knowledge. Much of what we think of as "modern cryptography" owes itself more to the kinds of information manipulation provided by PK than to the DES, which is often relegated to the role of a "black box" in a crypto protocol, interchangeable with IDEA or any other conventional cypher. It's more defensible to argue that strictly from the NSA's goal of reading other people's mail, DES was harmful by revealing a general approach for constructing strong conventional cyphers. But as far as stimulating the field of cryptography in general, I think PK has played a more important role. Hal Finney hfinney@shell.portal.com