Performance analysis of Format Preserving Encryption (FIPS PUBS 74-8) over block ciphers for numeric data

Abstract

Encrypting Credit card numbers, Social Security Numbers in huge legacy databases has become a very complex task as encrypted data normally increases in size and changes its format, with traditional encryption algorithms. A number of cryptographic methods have been introduced to provide security to credit card numbers. But, a major problem in adopting these cryptographic algorithms is the requirement to change the existing schema and underlying applications to incorporate the encrypted data. Format Preserving Encryption is a solution to the above mentioned problem, wherein the encrypted data `fits' into the existing schema. In this paper, we are analyzing the performance of Format Preserving Encryption (FIPS 74-8) over block ciphers such as AES, DES, 3DES, Blowfish on numeric data (credit cards numbers) with different keys. It has been observed that FPE (FIPS 74-8) over AES with 192 bits key gives better performance with 16198.5ns for an average encryption and decryption time of 1000 credit card numbers. Performances of Blowfish and AES with Key size 192 are neck to neck with respect to 1000 sixteen digits credit card numbers. We have also discussed overhead of FPE (FIPS-74-8). FIPS 74-8 was a NIST standard based on DES. Instead of using a block cipher DES, use of AES or Blowfish will give better performance and security for Format preserving of numeric data.