[Cryptography] Why are Diffie-Hellman key sizes multiples of 64?

[Peter Gutmann]

Jon Callas <jon at callas.org> writes:

>There's no math reason, it's an engineers-being lazy reason

It's not lazy or prudent, it's because people like round numbers.  Why are
nonces and keys 8 or 16 bytes and not 13, or 27?  Why are should-be-OK-for-
most-cases buffers 128 bytes, or 1024, or 1000 if you don't think in powers of
2?  Why does NIST match symmetric key sizes to illogical (and at the high end,
nonsensical) asymmetric ones?  People like their numerology.

73,
Peter.