Revisit reversible hash functions now that the CQF is available

[ctb]

See #1441, #1442.

Idea is that since the CQF stores hashes, we would be able to retrieve hashes and then reverse them to get the k-mers (at least for k <= 32).

@betatim suggests keywords "avalanching" ("“small change makes big change in the hash value”) and maybe symmetric ciphers

@ctb looking at bit relocation and this link and this link.

[ctb]

also see https://gist.github.com/betatim/1d4ee182a62d00afb93b8f239285b735

[ctb]

Heng Li to the rescue: https://gist.github.com/lh3/59882d6b96166dfc3d8d

[betatim]

You thinking https://gist.github.com/lh3/59882d6b96166dfc3d8d#64-bit-mix-functions ?

[ctb]

yes