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Apr
26
revised EC Schnorr signature: multiple standard?
improved formatting, numbered related questions
Apr
26
comment Give a simple hash chain example in Java
You'd need a salt as well to be reasonably secure for passwords. Use a PBKDF such as PBKDF2.
Apr
26
comment Give a simple hash chain example in Java
So why do you use MD5 in your example?
Apr
26
revised with RSA encryption, how do I find the md5sum of the private key from the public key?
added 260 characters in body
Apr
25
reviewed Approve MAC is constructed by hashing and then encrypting
Apr
25
comment Using Openssl Libarary to convert .key encoded to .pem
That's not what I asked.
Apr
25
comment Using Openssl Libarary to convert .key encoded to .pem
What program was used to create the .key file? Are you sure it wasn't encrypted with the public key? You cannot encrypt with the private key really (as anyone with the public key can decrypt, and the public key is supposed to be, well, public).
Apr
25
comment When to chose hardware accelerated crypto for Big Data
@SEJPM HSM's are usually focussed on high security applications. They are used by banks and CA's to keep their keys secure. When talking about TLS (as seems to be the case) they it's probably better to refer to the hardware as SSL accelerators. Note that there are certainly also TLS accelerators that turn a TLS connection into a TCP stream (contrary to what the Wikipedia page mentions).
Apr
25
answered Key management and derivation - Allow changing of the passphrase
Apr
23
revised Are there any practical attacks that create a printable chosen prefix MD5 collision?
edited title
Apr
23
comment SHA256(RsaPrivateKey) == AES key?
Not really no. Leaking the private key would do the trick.
Apr
22
revised SHA256(RsaPrivateKey) == AES key?
added 173 characters in body
Apr
22
answered SHA256(RsaPrivateKey) == AES key?
Apr
22
comment How secure is this logarithmic encryption algorithm?
Fractions and certainly floats are pretty tricky because of rounding errors and suchlike. There is a good reason why almost all cryptographic functions work with (positive) integers instead. @MrCyber I didn't see any mention of padding or hybrid cryptography (which may be needed for larger plaintext?) in the question.
Apr
22
comment How secure is this logarithmic encryption algorithm?
If you have small keys then brute forcing is always an option. Key size should not be related to message size. If that would be the case, how would you encrypt small messages?
Apr
21
comment Parallel file encryption and authentication for large files
Yeah, you could combine both approaches I suppose :)
Apr
21
comment Parallel file encryption and authentication for large files
Well you can always device a protocol that derives a new key with a new salt after 50GB. It would be a bit more complex though. If you're paranoid you could opt for a larger salt, say up to 128 bytes.
Apr
21
comment Parallel file encryption and authentication for large files
Well, you can always use an 8 byte salt per file and use a KBKDF to derive a key per file. Then you could use GCM to encrypt the blocks. Note that you don't need a parallel GCM implementation. You can use just use multiple instances of the same cipher. Your problem is already embarrassingly parallel, so the underlying algorithm doesn't need to be. I presume that - in general - your files won't be much over 60 GB, right?
Apr
21
comment Parallel file encryption and authentication for large files
You'd still need two passes, one for decryption and a full other just to check the hash. OCB would be one pass, but I'm not an expert on that mode or how it handles IV's. In general though you don't need a quick check. You don't expect MAC to fail at all, only when the ciphertext is changed.
Apr
21
answered Parallel file encryption and authentication for large files