Enhanced Security Encryption for Data Storage Using Multiple Keys

Abstract

Encryption of data has been a key issue in the global market as the technology advancement has brought high risk through unauthorized access, alteration, degradation, destruction, and other threats to the information that is being shared. For the solution to these problems, many algorithms have been designed to overcome the potential threats. My research also focuses on encrypting the data through efficient use of algorithm to make it secure. For this the use of multiple keys is an essential part. Key1 is a high entropy source where as key2 is a a pass phrase. Key1 is seeded with PRNG to generate 32 byte block which is then added to the beginning of the message. Encryption algorithm is designed to provide some protection for the user who re-uses the same pass phrase when encrypting various files. The algorithm will generate different cipher text even if it is invoked on the exact same plain text with the same pass phrase. This is accomplished by cascading a stream cipher with a block cipher. The block cipher is not cryptographically secure. Its purpose is to avalanche changes throughout the file. The first block is XORed with the hash of the pass phrase, the hash of the subsequent blocks are calculated from the plain text of the previous block concatenated with the hash used in the previous block. The stream cipher is a simple XOR against the next PRNG return and an XOR against the sum of all previous plain text modulo 256. Before starting encryption, the PRNG is seeded with high entropy data and used to generate a first block.