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Jul
14
comment How does NaCL Poly1305 implementation do modular multiplication?
There are Floodyberry's implementations. The poly1305-donna-unrolled variant can be easily ported to other languages. I'm working on one as well, but I'm not finished yet.
Jul
14
revised How does NaCL Poly1305 implementation do modular multiplication?
added 74 characters in body
Jul
14
comment How does NaCL Poly1305 implementation do modular multiplication?
It's funny that this implementation is used so often, given its bad performance.
Jul
14
revised How does NaCL Poly1305 implementation do modular multiplication?
added 74 characters in body
Jul
14
revised How does NaCL Poly1305 implementation do modular multiplication?
added 74 characters in body
Jul
14
answered How does NaCL Poly1305 implementation do modular multiplication?
Jul
14
awarded  Enlightened
Jul
14
awarded  Nice Answer
Jul
14
awarded  Custodian
Jul
14
reviewed Leave Open Efficient Incremental Updates to Large Merkle Tree
Jul
14
comment Technical feasibility of decrypting https by replacing the computer's PRNG
@Thomas I heard that Linux uses RdRand directly in some places instead of just mixing it into the pool. In that case you don't need to poison the entropy pool.
Jul
13
comment What is the purpose of update() in popular hash APIs?
Which requires putting the full message into a continuous piece of address space. So it needs unnecessary copying in some cases and doesn't fit at all for large inputs. With an update() based API I can easily hash a multi gigabyte file on a modest computer.
Jul
13
answered Efficient Incremental Updates to Large Merkle Tree
Jul
13
comment Efficient Incremental Updates to Large Merkle Tree
You can choose until which level you keep the tree. If you keep less of the tree updates become more expensive, but you need less memory.
Jul
12
comment What is the purpose of update() in popular hash APIs?
I still don't get your point. An update function that prepended the length would be broken since now calling update twice isn't equivalent to calling it once on a combined buffer.
Jul
12
comment What is the purpose of update() in popular hash APIs?
I don't get your point. What are you comparing update to?
Jul
12
comment What is the purpose of update() in popular hash APIs?
Why shouldn't it be there? What alternative do you propose?
Jul
12
comment Building a hard to factor number without knowing its factorization
AFAIK it is only possible with huge (and thus very inefficient) primes.
Jul
12
comment Review of AES encryption concept for an open source project
You should use a proper MAC in an encrypt-then-mac scheme, or standard authenticated encryption like AES-GCM.
Jul
11
comment Is OpenPGP vulnerable to the “crypto doom principle”?
Sign-then-Encrypt suffers from pretty much the same issues (padding oracles etc.) as MAC-then-Encrypt. I prefer Sign-then-Encrypt-then-MAC or Sign-then-AuthenticatedEncryption giving you the best of both worlds at moderate cost.