About AES Encryption & Decryption

The Advanced Encryption Standard (AES) is a symmetric block cipher that can encrypt and decrypt information. AES is NIST approved and recommended cryptographic algorithm that can be used to protect data. The AES algorithm capable of using cryptographic keys for 128, 192 and 256 bits to encrypt and decrypt data in blocks of 128 bits.

Cipher Modes

There are five confidentiality modes of operation for AES

• ECB (Electronic Codebook)
• CBC (Cipher Block Chaining)
• CFB (Cipher Feedback)
• OFB (Output Feedback)
• CTR (Counter)

Plain Text

Text that needs to be encrypted is referred as Plain Text

Cipher Text

Encrypted text is referred to as Cipher Text

Initialization Vector (IV)

The IV is used in an intial step in the encryption of a message and in the corresponding decryption of the message.

The IV value should be unique for each encryption operation, this will produce different output for same plain text and encryption key inputs. This prevents an hacker to find any pattern between Plain Text and Cipher Text. The IV is not a secret and it can be passed along with Cipher Text