Mar 20, 2014 · The key is 128 (binary) bits. That's all it means. AES supports key sizes of 128, 192, or 256 bits. AES has a fixed block size of 128 bits, which means it en/decrypts data in chunks of 16 bytes at a time. The plaintext/cipher text can be any length of course (and is padded out to a multiple of 16 bytes).

Mar 12, 2016 · Pode trabalhar com chaves de 128, 192 ou 256 bits (o algoritmo Rijndael, que originou o AES, permite mais tamanhos de chaves). Em outras palavras, é um algoritmo cuja função direta (cifragem) recebe como entradas um bloco de 128 bits (a mensagem) e uma chave do tamanho escolhido, e devolve uma saída também de 128 bits (a cifra).

Whether AES uses 128 or 256 bit mode depends on size of your key, which must be 128 or 256 bits long. Typically you don't use your password as a key, because passwords rarely have exact length as you need. Instead, you derive encryption key from your password by using some key derivation function.

Apr 14, 2009 · AES is a United States federal standard, FIPS 197, which is a subset of Rijndael: AES has a fixed block size of 128 bits and a key size of 128, 192, or 256 bits, whereas Rijndael can be specified with block and key sizes in any multiple of 32 bits, with a minimum of 128 bits and a maximum of 256 bits. From Advanced Encryption Standard on Wikipedia.

Oct 14, 2015 · Here aes-128-cbc and aes-128. aes stands for advanced encryption service, 128 is the bit rate, and CBC is the mode of encryption. However, this is recited and used only in OPEN SSL Formats. Prior to Open SSL, PHP used mcrypt_encrypt which was not properly designed (older versions of PHP). aes-128 can also be reffered to as rijndael while using ...

Mar 14, 2014 · The most simple one would be doing the modulo operation between an input number (an integer representation of your string, for example) and the maximum number that can be represented in n bits (in your case, 128); the output result will be an n-bit number that you can convert to whatever form you want (probably hexadecimal) and use it as an AES ...

With a random selection, the space of possible 128-bit IV is large enough that collisions are extremely improbable. Actually, that's why AES uses 128-bit blocks (thus implying 128-bit IV). The entity which will decrypt the message must know the IV, so you have to store it along with the encrypted message. That's an extra 16 bytes.

AES is a block cipher meaning a short cleartext will be padded out to 128 bits or 256 bits before encrypting. The output you don't like is exactly 256 bits, which is a proper length; the output of your C program is 128 bits long. The two libraries have different default block sizes. This is independent of key length. –

Jun 14, 2013 · AES keys need to be exactly 128, 192 or 256 bits long. So passwords of arbitrary length won't work in your situation right away, but using a "normal" password of the right size is also wrong, because these kinds of passwords do not contain enough entropy and will allow attackers to brute-force them more easily because they are not random enough.

Dec 11, 2010 · This exception basically occur due to length of key that you hava passed for encryption.If you are using AES encryption then the number of characters must be in length of 128/192/256 bits. For example you can use the key of 16 character,24 character or 32 character. String encrypted_data=AES.encrypt("HELLO","ASDFGHJKLASDFGHJ"); Hope this help...