Sometimes one just has 128 bit inputs (and outputs), however Haraka is specified only for 256 (and 512) bits.
Thus the question is how one would use (or adapt) Haraka to fit such a use-case?
(Where would such a thing be helpful? For example I'm experimenting with large immutable hash tables where the keys are 128 bits, and I need only 64+32 bits from the resulting hash.)
I see three broad possibilities:
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looking at the symmetry between the 256 and 512 variants, one 2 lane the other 4, one could implement Haraka 128 as a 1 lane variant of the two; this implies no mixing step, just straight aesenc -> aseenc -> ... -> aesenc with different round keys;
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using Haraka 256, and using only one of the states as the output; however how should one feed the input when one has only 128 bits? one solution would be value and ~value;
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using Haraka 256 (like above), but returning the s0 XOR s1;
Sometimes one just has 128 bit inputs (and outputs), however Haraka is specified only for 256 (and 512) bits.
Thus the question is how one would use (or adapt) Haraka to fit such a use-case?
(Where would such a thing be helpful? For example I'm experimenting with large immutable hash tables where the keys are 128 bits, and I need only 64+32 bits from the resulting hash.)
I see three broad possibilities:
looking at the symmetry between the 256 and 512 variants, one 2 lane the other 4, one could implement Haraka 128 as a 1 lane variant of the two; this implies no mixing step, just straight
aesenc -> aseenc -> ... -> aesencwith different round keys;using Haraka 256, and using only one of the states as the output; however how should one feed the input when one has only 128 bits? one solution would be
valueand~value;using Haraka 256 (like above), but returning the
s0 XOR s1;