AES (Advanced Encryption Standard) is a widely adopted symmetric block cipher algorithm used to encrypt electronic data. Here’s a breakdown of what that means:
- Symmetric: It uses the same secret key for both encrypting (scrambling) and decrypting (unscrambling) data. This means that both the sender and the receiver of the encrypted information must possess the same key.
- Block Cipher: It operates on fixed-size blocks of data. For AES, the block size is 128 bits. If the data to be encrypted is larger than a block, it’s divided into these 128-bit blocks, and each block is encrypted individually (often in conjunction with an operating mode to ensure security across multiple blocks).
- Algorithm: It’s a well-defined set of computational steps that transform plaintext (readable data) into ciphertext (unreadable, encrypted data) and vice versa.
Key characteristics of AES:
- Key Sizes: AES supports three different key lengths:
- AES-128: Uses a 128-bit key.
- AES-192: Uses a 192-bit key.
- AES-256: Uses a 256-bit key. Longer key lengths generally provide stronger security as they exponentially increase the difficulty of a brute-force attack (trying all possible keys).
- Rounds: The encryption process involves multiple rounds of transformations that include substitution, permutation, and mixing of the data based on the key. The number of rounds depends on the key size (10 rounds for 128-bit, 12 for 192-bit, and 14 for 256-bit).
- Security: AES is considered highly secure against all known practical attacks when implemented correctly with a sufficiently long key. AES-256 is often regarded as virtually unbreakable by brute force with current technology.
- Efficiency: AES is relatively fast and efficient to implement in both software and hardware.
- Standard: It was established as a standard by the U.S. National Institute of Standards and Technology (NIST) in 2001 and has since become a global standard for securing sensitive data.
In essence, AES is a fundamental building block in cybersecurity, used to ensure the confidentiality of digital information across various applications, including:
- Secure websites (TLS/SSL)
- Wireless security (WPA2/WPA3)
- Virtual Private Networks (VPNs)
- File and disk encryption
- Secure storage of passwords
- Many other systems requiring data protection.