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bio website github.com/CodesInChaos
location Frankfurt, Germany
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visits member for 3 years, 5 months
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Jul
27
revised How strong is the ECDSA algorithm?
deleted 2 characters in body; edited tags
Jul
27
revised Encryption vs. decryption of same plaintext
added 2 characters in body; edited tags; edited title
Jul
27
revised RS Erasure Coding and Shamir's Secret Sharing
Removing security tag - see http://meta.crypto.stackexchange.com/q/181/2511
Jul
27
revised Is a random length-extension worth the effort?
deleted 2 characters in body; edited tags
Jul
27
revised How big an RSA key is considered secure today?
edited tags
Jul
27
revised How secure is my OTP program?
edited tags
Jul
27
revised Can I jettison MAC if I already have SHA1(M)?
removed security tag
Jul
26
revised Can I pre-define the points in Shamir's Secret Sharing algorithm
edited tags
Jul
26
asked Purpose of outer key in HMAC
Jul
26
comment Are mouse movement coordinates useful as a seed for a RNG?
A 64 bit seed is far too small to be secure. And a single mouse position doesn't even have close to 64 bits of entropy. It doesn't even have 20 bits of entropy.
Jul
26
comment Are mouse movement coordinates useful as a seed for a RNG?
Why don't you just use the random number generator built into your operating system?
Jul
25
comment Signature and Timestamp for Long Term Document Archival Question
Aren't there some timestamp services that are based on publishing hashes?
Jul
22
comment Using same keypair for Diffie-Hellman and signing
The master key approach doesn't help either, since I try to minimize the size of the public key. I considered using the hash of two separate public keys, but that's annoying in some of my intended uses. After reading the paper I linked, I think the risk of using EC-DH + EC-Schnorr is acceptable compared to the risk of mistakes in other security relevant parts of the protocol and implementation.
Jul
22
comment Using same keypair for Diffie-Hellman and signing
The first distinction is not between encryption and signatures, it's between authentication and confidentiality keys. In particular if you authenticate emails using a key-exchange based algorithm[Which I prefer over signatures], it has the same life cycle as a key used for signing.
Jul
22
comment Can ECDSA signatures be safely made “deterministic”?
Related blog entry: Surviving a bad RNG Scroll down to ECDSA signatures
Jul
22
revised Using same keypair for Diffie-Hellman and signing
added 164 characters in body; edited tags
Jul
22
answered Using same keypair for Diffie-Hellman and signing
Jul
21
comment Can I jettison MAC if I already have SHA1(M)?
@Fixee If you validate the padding first, and only then hash, and attacker might be able to use that to decrypt the message, even if he can't replace it by his own.
Jul
21
awarded  Yearling
Jul
21
answered Can I jettison MAC if I already have SHA1(M)?