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comment Are there any elliptic curve asymmetric encryption algorithms?
@DrLecter - thanks for humouring me. You should post it as an answer.
Apr
15
comment Are there any elliptic curve asymmetric encryption algorithms?
@CodesInChaos - Why? Curiosity... nothing more. I'm not researching this for a practical application.
Apr
14
comment Are there any elliptic curve asymmetric encryption algorithms?
@DrLecter - From what I understand, ECIES uses symmetric encryption (albeit with a shared secret, derived by means of asymmetric cryptography), does it not? I'm looking for asymmetric encryption. I did say scheme, so perhaps I should have been more explicit. I want to know whether there's an algorithm that employs ECC that is similar to RSA in that a short message can be encrypted with a public key, and decrypted with a private key.
Apr
9
comment Secure AES Key Generation via Salsa20?
A correct implementation isn't enough - you also need to know how to use it correctly. There's no "winner", per se. It just depends on your requirements/circumstances... but without having made a case for managing your own CSPRNG (and it is hands on), I'd definitely suggest you use /dev/random. Anything beyond this - I suggest posting another question (assuming your own research doesn't answer any further questions you might have).
Apr
9
comment Secure AES Key Generation via Salsa20?
They're both CSPRNGs, yes. If you don't have much experience in crypto, and you've got no good reason to implement your own CSPRNG (such as Fortuna), then /dev/random is a much safer bet. You don't have to concern yourself with entropy, seed-life, etc.
Apr
9
comment Secure AES Key Generation via Salsa20?
@XCore - Yes, Fortuna is another CSPRNG that uses a symmetric block-cipher as one of its internal mechanisms.
Apr
8
comment SHA256-based stream cipher
+1 for pointing out the lack of authentication. AES-GCM seems like a much better option.
Apr
8
comment SHA256-based stream cipher
Unbreakable? That's a bold claim.
Apr
7
comment Convert SpookyHash to semi-secure 192bit hash
@e-sushi - you understood perfectly well ;-)
Apr
7
comment Convert SpookyHash to semi-secure 192bit hash
"How secure will this function be?" Semi.
Apr
5
comment Wrong Test Vector for HKDF with HMAC-SHA256
I can also confirm that I'm getting the expected results as per that test vector
Mar
27
comment Is Curve25519-java secure?
@CodesInChaos - are the signatures in Curve25519-java not deterministic? Maybe I'm missing something, but I thought they were.
Mar
27
comment Difference between lightweight, online and low memory Authenticated Encryption schemes
@figlesquidge .. +1
Mar
21
comment Difference between lightweight, online and low memory Authenticated Encryption schemes
@figlesquidge - I guess the question being closed because it's "unclear what you're asking" suffices in lieu of comments. I second Rath's comment. In my opinion, the question seems extremely vague, and too broadly open to interpretation. Adding some links, references, and/or previous research to the question might help provide context, and make the question answerable. However, if this question seems clear to you - go ahead and answer it.
Mar
10
comment Breaking Double Encryption
Related reading...
Mar
5
comment Entropy of Androids motion-sensor data
I disagree with those who say this is off-topic (although you might want to get rid of the code, as it's superfluous to your question). You're basically asking whether external input collected via a device's sensors has high entropy, and is suitable for feeding into a well-vetted CSPRNG. You should check out this question ... I would say the same principles apply.
Feb
19
comment How can PBKDF2 be used to hash passphrases for ed25519 signing keys?
PBKDF2 is deterministic. Provided that the same salt is used, the output will be the same when using the same input repeatedly.
Jan
30
comment Best way to get 32 bytes from PBKDF2
If you just want to use a single primitive (ie, PBKDF2), I'd recommend reading D.W's excellent answer here: crypto.stackexchange.com/questions/8232/…
Nov
29
comment What would make it impossible to deny that decryption of a package has taken place?
I don't think this is strictly possible with crypto alone... it's more of a software/protocol problem. If you can assume that the server only delivers the data to be decrypted once the user has been authenticated, and that decrypting the data is trivial (ie, that particular user has the key to decrypt it), then it's probably safe to say that the data has been decrypted by that user, meaning that the server can make a note of it's retrieval/decryption. Vaguely related are time-sensitive crypto questions here and here.
Nov
28
comment What is 'key agility' in relation to symmetric-key encryption?
Poor key agility can be an advantage in some situations. The slow/expensive key initialization (ie, key agility) in Blowfish means that it's more immune to brute-force attacks.