I have a file encrypted with AES-256 using libgcrypt's CTR mode implementation. I want to be able to decrypt the file in parts (e.g. decrypting blocks 5-10 out of 20 blocks without decrypting the w...

How to detect if a message was crypt by CBC or ECB mode? I have made a function who encrypt in AES 128 CBC or ECB randomly, and I do hamming between clear text and cipher text, but seams not corr...

I've generated a random 256 bit symmetric key, in a file, to use for encrypting some data using the OpenSSL command line which I need to decrypt later programmatically using the OpenSSL library. I'...

I need an algorithm that can do a one-to-one mapping (ie. no collision) of a 32-bit signed integer onto another 32-bit signed integer. My real concern is enough entropy so that the output of the fu...

I got this code from http://www.ravenblast.com/index.php/blog/android-password-text-encryption/ and, although it works, I have a growing suspicion it's not secure enough. There isn't any initializa...

A short while ago a paper got published on PRESENT: An Ultra-Lightweight Block Cipher by Andrey Bogdanov et al becoming ISO standard 29192-2:2012. Is there anyone that has a C#, Delphi or FreePasc...

I am making a protocol that uses packets (i.e., not a stream) encrypted with AES. I've decided on using GCM (based off CTR) because it provides integrated authentication and is part of the NSA's Su...

from what I know, CTR mode doesn't use an Initial Vector. It just takes a counter, encrypts it with a given key and then XOR's the result with the plaintext in order to get the ciphertext. Other b...