Block encryption method and schemes for data confidentiality and integrity protection

• US 20060056623A1
• Filed: 11/07/2005
• Published: 03/16/2006
• Est. Priority Date: 01/31/2000
• Status: Abandoned Application

• Current Assignee: Vdg, Inc.
• Original Assignee: Vdg, Inc.
• Inventors: Donescu, Pompiliu, Gligor, Virgil Dorin
• Application Number:
  US11/267,146
• Publication Number:
  US 20060056623A1
• Time in Patent Office: Days
• US Class Current: 380/28
• CPC Class Codes: H04L 2209/08 Randomization, e.g. dummy operations or using noise
• CPC Class Codes: H04L 2209/125 Parallelization or pipelining, e.g. for accelerating processing of cryptographic operations
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• CPC Class Codes: H04L 9/0637 Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/0656 Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC

Abstract

A block encryption method and schemes (modes of operation) that provide both data confidentiality and integrity with a single cryptographic primitive and a single processing pass over the input plaintext string by using a non-cryptographic Manipulation Detection Code function for secure data communication over insecure channels and for secure data storage on insecure media. The present invention allows, in a further aspect, software and hardware implementations, and use in high-performance and low-power applications, and low-power, low-cost hardware devices. The block encryption method and schemes of this invention allow, in yet a further aspect, encryption and decryption in parallel or pipelined manners in addition to sequential operation. In a yet further aspect, the block encryption method and schemes of this invention are suitable for real-time applications.

Claims

1. An encryption method comprising the steps of:

receiving an input plaintext string comprising a message;

partitioning the input plaintext string into a plurality of equal-size blocks;

creating an MDC block that includes the result of applying a non-cryptographic Manipulation Detection Code (MDC) function to the plurality of the equal-size blocks;

making one and only one processing pass with a single cryptographic primitive over each of said equal-size blocks and the MDC block to create a plurality of hidden ciphertext blocks; and

performing a randomization function over said plurality of hidden ciphertext blocks to create a plurality of output ciphertext blocks.

2. A decryption method that is the inverse of an encryption method, comprising the steps of:

presenting a string including ciphertext string for decryption;

partitioning said ciphertext string into a plurality of ciphertext blocks;

selecting n+1 ciphertext blocks from said plurality of ciphertext blocks representing n data blocks and one Manipulation Detection Code (MDC) block and performing a reverse randomization function on each of the selected n+1 ciphertext blocks to obtain a plurality of hidden ciphertext blocks;

making one and only one processing pass with a single cryptographic primitive that is the inverse of an encryption single cryptographic primitive over the plurality of hidden ciphertext blocks to obtain a plurality of plaintext blocks;

verifying integrity of the plaintext blocks using a non-cryptographic MDC function;

outputting the plurality of plaintext blocks as an accurate plaintext string if the integrity verification passes; and

outputting a failure indicator if the integrity verification fails.