In cryptography Triple DES (3DES) is the common name for the Triple Data Encryption Algorithm (TDEA) block cipher, which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Because the key size of the original DES cipher was becoming problematically short, Triple DES was designed to provide a relatively simple method of increasing the key size of DES to protect against brute force attacks without designing a completely new block cipher algorithm.