| As David Wagner points out, encryption with a public key (for which the
| private key has been discarded) would seem to work.
There's something seriously wrong here, however. There are many close, but
not identical, definitions, of a one-way hash. While none of them explicitly
say so, many *use
| > it came up lately in a discussion, and I couldn't put a name to it:
| > a means to use symmetric crypto without exchanging keys:
| >
| > - Alice encrypts M with key A and sends it to Bob
| > - Bob encrypts A(M) with key B and sends it to Alice
| > - Alice decrypts B(A(M)) with key A, leav
