Changes between Version 8 and Version 9 of OneHundredYearCryptography

Timestamp:

2011-02-16T07:25:53Z (14 years ago)

Author:

zooko

Comment:

update about hash function combiners (not sure yet which ones should be used in which cases -- certainly in hash-based digital sigs Comb4P would be a performance problem and overkill)

OneHundredYearCryptography

@@ -18 +18 @@
 == Hashing ==
 
-We'll combine two hash functions using the Comb4P hash function combiner, which preserves most (but not all) security properties of the hashes. It also has the advantage of being simple and relatively fast, though because the extra work comes in the form of a set of final Feistel rounds, this may negatively effect performance when combined with the tree hashing mode Tahoe uses.
+We'll combine two hash functions using an appropriate combiner depending on the hash function properties that are required, see [http://tahoe-lafs.org/pipermail/tahoe-dev/2010-June/004575.html Zooko's notes] about hash function combiners. The Comb4P hash function combiner preserves most (but not all) security properties of the hashes is safest combiner in case we actually rely on a hash function property, though because the extra work comes in the form of a set of final Feistel rounds, this may negatively effect performance when combined with the tree hashing mode Tahoe-LAFS uses.
 
 == Signatures ==