The Secret Security Wiki


Advanced Encryption Standard

Advanced Encryption Standard (AES) is a symmetric block cipher used extensively in industry and government. The United States National Institute of Standards and Technology (NIST) developed AES to replace Data Encryption Standard (DES), for which various attacks began to be published.

In its requirements, NIST specified the new advanced encryption standard algorithm must be a block cipher capable of handling 128 bit blocks, using keys sized at 128, 192, and 256 bits.

The cipher itself was proposed by Belgian cryptographers Daemen and Rijmen as part of a NIST call for proposal for a new symmetric key algorithm. NIST required any proposals to be fully open to public scrutiny and comment, to ensure a thorough, transparent analysis of the designs submitted.

In October 2000, NIST published AES as U.S. FIPS PUB 197.

  • What is the size of the AES encryption key used by CCMP?

    Counter Mode Cipher Block Chaining Message Authentication Code Protocol (CCMP) is an encryption protocol designed for Wireless LAN products that implements the standards of the IEEE 802.11i amendment to the original IEEE 802.11 standard. CCMP is an enhanced data cryptographic encapsulation mechanism designed for data confidentiality. It was created to address the vulnerabilities uncovered for WEP.

    CCMP uses an AES 128 bit key.

  • Why is DES no longer secure?

    DES encryption can be broken using brute force and other more efficient attacks, and is therefore no longer in use.

  • Is Blowfish faster than AES?

    Blowfish, when implemented in software, can be faster than AES, depending on the implantation. That said, many modern processors have hardware accelerators for AES which makes AES much faster. There are no similar accelerators for Blowfish.

  • Is Blowfish more secured than AES?

    AES encryption has undergone rigorous testing from both benevolent and malevolent attackers, and has yet to be broken, which is part of the reason it has become the industry standard for data security. Blowfish encryption is less popular than AES, so it hasn’t been subjected to as much scrutiny and attacks.

  • What is the difference between the AES and RSA?

    AES is a symmetric block cipher and RSA is an asymmetric cipher.