4,779 reputation
1734
bio website
location Netherlands
age 40
visits member for 2 years, 10 months
seen 2 hours ago

Java and security expert with over 10 years of experience with the language and with the practical application of cryptographic protocols - including the design of protocols within international standardization bodies. Creator of a heavily used common criteria certified product. Over 30 years of experience with computers. Likes kids, cats, reading, movies and several sports.


2h
comment Does a stream cipher require a KDF when it's key is variable length?
Gotta sleep, I'll try and rewrite the text a bit tomorrow.
2h
answered Does a stream cipher require a KDF when it's key is variable length?
2h
comment Protection of Elliptic Curve Implementations against side-channel attacks
@CodesInChaos You are probably right, but does it invalidate the question enough to close it?
1d
comment Cryptography system that limits the length of the encypted message
Thank you for telling me all that, Tianren Lu, I never would have guessed.
1d
awarded  Fanatic
1d
comment Cryptography system that limits the length of the encypted message
Sorry, but a one time pad is basically a theoretical construct. Using it for a practical application such as SMS encryption is not a good idea. Using a stream cipher could work, but you would make sure that both sides stay in sync somehow.
1d
comment Implementation of garbled circuits using RSA
@ThomasM.DuBuisson Maybe change that into an answer? Negative answers are answers just as well.
1d
comment problem with “one time pad”
This is pretty well explained by - for instance - Boneh, isn't it? The idea of such practice is that you learn to do this yourself.
1d
comment SHA-1 collision resistance
Anything missing from the given answer, dear new user? It's been a while.
Oct
17
comment Elliptic curve parameters
I don't think you can validate outputs efficiently by hand. If you have a well described question for a specific implementation you could post on StackOverflow.
Oct
16
comment Encrypting twice with different modes?
How much more difficult than AES-256 in CTR mode? If the CTR is well applied, that question doesn't make much sense. Assumed that they could brute force 128/256 bit AES keys? You might as well assume that the attacker already has the keys, that would be a much more believable scenario.
Oct
16
comment HMAC_DRBG Generate Process: requesting N bytes at once different from requesting N bytes in total?
Or maybe I'm just too used to the properties of KBKDFs :)
Oct
16
asked HMAC_DRBG Generate Process: requesting N bytes at once different from requesting N bytes in total?
Oct
16
comment Does NSS fully implement PKCS 11?
OK, but I don't see anything in your question that assumes that this is about using the PKCS#11 interface from NSS. Especially the title seems contradictory. And I think that your comment about the PKCS#11 functions supported by NSS basically answers your own question :)
Oct
16
revised Comparing Files: Is it better to use multiple hash algorithms or just one?
added 72 characters in body
Oct
16
comment Comparing Files: Is it better to use multiple hash algorithms or just one?
OK, I see now. Sorry about that, you can just run until you find an inequality, and only test further if you don't find any. Slightly different use case as within most schemes.
Oct
16
revised AES: Guess Password using the unencrypted text?
added 174 characters in body
Oct
15
comment AES: Guess Password using the unencrypted text?
Well, the lazy was a bit tongue in cheek. PGP makes a lot of sense here and you can encrypt without providing a password at all.
Oct
15
comment Comparing Files: Is it better to use multiple hash algorithms or just one?
@Gutblender True, makes much less sense for small files. Although hashes of course are really small, 32 bytes at most. And you could create a hash tree and check a complete folder at once as well.
Oct
15
comment Comparing Files: Is it better to use multiple hash algorithms or just one?
I understand that, but are you only going to copy files with no obvious inequalities? So, if there is no obvious inequality, you leave it? Wouldn't that cause corruption?