US 2010/0074441 A1 · Data processing systems with format-preserving encryption and decryption engines

Abstract

A data processing system is provided that includes format-preserving encryption and decryption engines. A string that contains characters has a specified format. The format defines a legal set of character values for each character position in the string. During encryption operations with the encryption engine, a string is processed to remove extraneous characters and to encode the string using an index. The processed string is encrypted using a format-preserving block cipher. The output of the block cipher is post-processed to produce an encrypted string having the same specified format as the original unencrypted string. During decryption operations, the decryption engine uses the format-preserving block cipher in reverse to transform the encrypted string into a decrypted string having the same format.

Claims22

Dependent claims

A method for encrypting a data string using an encryption engine in a data processing system, comprising:

obtaining a data string containing characters, wherein the data string has a format specifying a legal set of character values for each of its characters;
processing the data string to remove any extraneous characters from the data string that are present;
encoding the processed data string using at least one index of sequential index values each of which corresponds to a respective one of the character values in the legal set of character values;
encrypting the encoded data string using a format-preserving block cipher;
and
using the index, decoding the encrypted encoded data string to produce a decoded encrypted data string with characters in the legal set of characters.

3 more elements

Dependencies are inferred from the claim text.

Data processing systems with format-preserving encryption and decryption engines

Life of this patent

Data processing systems with format-preserving encryption and decryption engines

Life of this patent

Abstract

Claims22