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Mar
9
comment CTR HMAC SHA256 implementation
@JohnSmith Because combining them is tricky (see the threads I link to). “Creating your own” is bad because you're using primitives whose behavior is not well-known, so it's delicate at best to use them correctly. In the case of HMAC+CTR, it's known that it's a tricky combination, and neither encrypt-then-mac nor mac-then-encrypt can be used without being very very careful. Using a known authenticated encryption mode frees you of this concern.
Mar
9
comment CTR HMAC SHA256 implementation
@JohnSmith But combining them makes a new mode, AES-CTR+HMAC-SHA256.
Mar
9
answered CTR HMAC SHA256 implementation
Mar
9
reviewed Close how to integrate 2-3 algorithms to encrypt large data fastly and securely insted using AES?
Mar
9
reviewed Close Known plaintext, unknown 128 bit block cipher
Mar
9
comment Known plaintext, unknown 128 bit block cipher
With modern ciphers, it's impossible to reverse engineer an encryption algorithm by looking at (plaintext, ciphertext) pairs. You need to reverse engineer the encryption or decryption code instead.
Mar
8
reviewed Leave Open Standard serialization format for libsodium-based messages
Mar
8
comment Standard serialization format for libsodium-based messages
I'm voting to leave this question open because it is to a large extent about choosing the right kind of cryptographic primitive and passing it appropriate arguments. It isn't just an implementation question but also a cryptographic protocol design question.
Mar
8
reviewed Close Separate keys for encryption and MAC?
Mar
8
comment Standard serialization format for libsodium-based messages
You've missed the point of the question, which is to store a cookie in an untrusted location, so that the cookie needs to be at least authenticated upon reading.
Mar
7
reviewed Close Will SHA1 or Other Hash Functions Ever Contain Quotes
Mar
7
comment Will SHA1 or Other Hash Functions Ever Contain Quotes
I'm voting to close this question as off-topic because it is about programming, with cryptography only involved tangentially. It would be on-topic on Stack Overflow.
Mar
4
reviewed Leave Closed How to compare between two cryptographic algorithms in terms of security?
Mar
3
reviewed Reviewed Is Chaocipher a secure cipher under ciphertext-only attack?
Mar
3
reviewed Leave Open Predicting Google Authenticator OTP Codes
Mar
2
reviewed Reviewed How to choose the integer m in the general number field sieve (GNFS)?
Mar
2
reviewed Leave Open Are there cryptographic schemes that mask as unencrypted traffic?
Mar
2
reviewed Close Pseudorandom function and hash function
Mar
2
reviewed Leave Open Why would cryptography fall apart if there were a finite number of primes?
Mar
2
reviewed Reopen Vigenere ciphers : Need help for math analysis