AES Encryption – Key versus IV

As you can see from the other answers, having a unique IV per encrypted file is crucial, but why is that? First – let’s review why a unique IV per encrypted file is important. (Wikipedia on IV). The IV adds randomness to your start of your encryption process. When using a chained block encryption mode … Read more

How does a cryptographically secure random number generator work?

A cryptographically secure number random generator, as you might use for generating encryption keys, works by gathering entropy – that is, unpredictable input – from a source which other people can’t observe. For instance, /dev/random(4) on Linux collects information from the variation in timing of hardware interrupts from sources such as hard disks returning data, … Read more

encryption/decryption with multiple keys

GnuPG does multi-key encryption in standard. The following command will encrypt doc.txt using the public key for Alice and the public key for Bob. Alice can decrypt using her private key. Bob can also decrypt using his private key. gpg –encrypt –recipient [email protected] \ –recipient [email protected] doc.txt This feature is detailed in the user guide … Read more

Example of AES using Crypto++ [closed]

Official document of Crypto++ AES is a good start. And from my archive, a basic implementation of AES is as follows: Please refer here with more explanation, I recommend you first understand the algorithm and then try to understand each line step by step. #include <iostream> #include <iomanip> #include “modes.h” #include “aes.h” #include “filters.h” int … Read more