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bio website github.com/CodesInChaos
location Frankfurt, Germany
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visits member for 3 years
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Jul
31
reviewed Edit suggested edit on Is Wiener's attack on RSA extendable to larger keys with low hamming weight?
Jul
31
revised Is Wiener's attack on RSA extendable to larger keys with low hamming weight?
Corrected formatting.
Jul
31
comment Why elgamal is still discussed
I agree with you. ElGamal is only useful in niche applications. For normal usage DH is preferable.
Jul
31
comment Practical consequences of using functional encryption for software obfuscation
@rath AVs are practically irrelevant for keeping your computer secure. The only reason for having them is to avoid the accusation of negligence for not having one.
Jul
31
revised Derive a key from public data using a secret master key
added 271 characters in body
Jul
31
comment Derive a key from public data using a secret master key
@RickyDemer The OP won't derive 2^60 keys, so that doesn't matter. For reasonably sized outputs AES-CTR is indistinguishable from random data. And even if you'd go above the birthday bound, it'd most likely stay secure despite indistinguishably breaking down. So I wouldn't worry about the birthday bound.
Jul
31
comment Derive a key from public data using a secret master key
NIST has also published an AES based variant of HKDF. Might want to look for that one. But personally I prefer hashes for key derivation in most situations.
Jul
31
comment Derive a key from public data using a secret master key
If you encrypt a unique block with AES you get a unique output, and key recovery is hard. So I don't see a problem with your scheme as long as you only encrypt a single block.
Jul
31
comment Derive a key from public data using a secret master key
is your message longer than one block?
Jul
31
revised Derive a key from public data using a secret master key
added 6 characters in body
Jul
31
comment Derive a key from public data using a secret master key
Not sure what you mean by "brute force attack is plausible" in the context of HKDF. Your scheme and HKDF seem to aim at the same context, where you have a strong master key.
Jul
31
answered Derive a key from public data using a secret master key
Jul
30
comment Why use variable p, q, g for Diffie-Hellman?
My impression is that most protocols support arbitrary finite fields, but implementations usually choose a standard curve.
Jul
30
revised Quantum resistance of Lamport signatures
edited tags
Jul
30
revised understanding forking lemma
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Jul
30
revised Why is feed-forward mechanism used in hash functions?
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Jul
30
revised Why use variable p, q, g for Diffie-Hellman?
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Jul
30
comment Why use variable p, q, g for Diffie-Hellman?
Isn't that an advantage of standard groups? Since for those you can easily check if they were generated properly e.g. checking that the $p$ is a safe prime, or that the groups is a schnorr group with properly sized factors.
Jul
30
comment Why use variable p, q, g for Diffie-Hellman?
What's the problem of the knowing factorization of the order? AFAIK it is usually known. Finite fields used with DH are usually based on a safe prime or are schnorr-groups. In both cases the prime factors of the order are known.
Jul
30
revised Efficient Incremental Updates to Large Merkle Tree
edited tags