Cipher mechanisms with fencing and balanced block mixing

• US 5,623,549 A
• Filed: 01/30/1995
• Issued: 04/22/1997
• Est. Priority Date: 01/30/1995
• Status: Expired due to Term

• Current Assignee: Terry F. Ritter
• Original Assignee: Terry F. Ritter
• Inventors: Ritter, Terry F.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/380,960
• Time in Patent Office: 813 Days
• Field of Search: 380/37, 380/42, 380/36
• US Class Current: 380/37
• CPC Class Codes: H04L 2209/08 Randomization, e.g. dummy operations or using noise
• CPC Class Codes: H04L 9/0625 with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI

Abstract

An enhanced cryptographic mechanism employs Latin square derived balanced size-preserving block mixers and strong, practical fencing arrays of substitution mechanisms in combination with each other and with block ciphers. Ciphers are expanded into efficient, larger, stronger versions. Block ciphers, in combination with balanced block mixers and/or with substitution mechanisms, produce cryptographic mechanisms with block sizes that are combinations of the sizes of the block ciphers. Ciphers using large data blocks can reduce data expansion to levels normally consistent with small blocks. Different sized enhanced cryptographic mechanisms are used in a multiple-size cryptographic mechanism to minimize wasted block space in a ciphered message. The cryptographic mechanism provides at least three layers of processing. In one embodiment a message passes through a fencing array of substitution mechanisms, balanced block mixers, multiple block ciphers, balanced block mixers, and another fencing array of substitution mechanisms, for encryption and decryption, yet still ciphers at a rate near that of the block ciphers alone.

Claims

1. An invertible balanced block mixer cryptographic mechanism for mixing each of some number x input blocks of some block size into each of said number x output blocks of said block size, comprising:

said number x mutually orthogonal latin square mixing or combiner mechanisms of order 2 to the power n, where n is said block size in bits.

2. A balanced block mixer mechanism for the invertible mixing of two input blocks of some block size n in bits into two output blocks of said block size n, comprising:

A first latin square mixing mechanism of order 2 to the power n for combining said two input blocks into the first of said two output blocks; and

A second latin square mixing mechanism of order 2 to the power n, orthogonal to said first latin square mixing mechanism, for combining said two input blocks into the second of said two output blocks.

3. The invertible mixer of claim 2 wherein the latin square mixing used in at least one said latin square mixing mechanism is explicitly described in an array.

4. The invertible mixer of claim 2 wherein the latin square mixing used in at least one said latin square mixing mechanism is implicitly described by a pre-determined computation.

5. The balanced block mixing method for the invertible mixing of two input blocks of some block size n in bits into two output blocks of said block size n, comprising the steps of:

combining the two input blocks by using a first latin square mixing of order 2 to the power n to produce the first of said two output blocks; and

combining the two input blocks by using a second latin square mixing of order 2 to the power n, orthogonal to said first latin square mixing, to produce the second of said two output blocks.

6. The invertible mixing method of claim 5, wherein at least one said latin square mixing is described in an array.

7. The invertible mixing method of claim 5, wherein at least one said latin square mixing is described by a pre-determined computation.

8. A balanced block mixer cryptographic mechanism for mixing each of some number n greater than 2 input blocks of some block size into each of said number n output blocks of said block size, comprising:

said number n mutually orthogonal latin square mixing or combiner mechanisms of order 2 to the power n, where n is said block size in bits.

9. A balanced block mixer mechanism for mixing two input blocks of some block size n in bits into two output blocks of said block size n, comprising:

a first latin square of order 2 to the power n, described in an array, for combining said two input blocks into the first of said two output blocks; and

a second latin square of order 2 to the power n, described in an array, orthogonal to said first latin square, for combining said two input blocks into the second of said two output blocks.

10. The method of using an inverse to an original orthogonal latin squares mixing of order 2 to the power n, where n is the block size in bits, to recover the original input values from each mixed result, comprising the steps of:

producing an inverse orthogonal latin squares mixing of order 2 to the power n, which is the inverse to said original orthogonal latin squares mixing; and

for each said mixed result, presenting said mixed result to said inverse latin squares mixing and collecting said original input values from the result of that mixing.