[aes] Comparison of DES, Triple DES, AES, blowfish encryption for data

The encryption methods described are symmetric key block ciphers.

Data Encryption Standard (DES) is the predecessor, encrypting data in 64-bit blocks using a 56 bit key. Each block is encrypted in isolation, which is a security vulnerability.

Triple DES extends the key length of DES by applying three DES operations on each block: an encryption with key 0, a decryption with key 1 and an encryption with key 2. These keys may be related.

DES and 3DES are usually encountered when interfacing with legacy commercial products and services.

AES is considered the successor and modern standard. http://en.wikipedia.org/wiki/Advanced_Encryption_Standard

I believe the use of Blowfish is discouraged.

It is highly recommended that you do not attempt to implement your own cryptography and instead use a high-level implementation such as GPG for data at rest or SSL/TLS for data in transit. Here is an excellent and sobering video on encryption vulnerabilities http://rdist.root.org/2009/08/06/google-tech-talk-on-common-crypto-flaws/