last modified: 26-MAR-1991 | catalog | categories | new | search |

NESC9839 PDES.

PDES, Fips Standard Data Encryption Algorithm

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1. NAME OR DESIGNATION OF PROGRAM:  PDES.
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2. COMPUTERS
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Program name Package id Status Status date
PDES NESC9839/01 Tested 26-MAR-1991

Machines used:

Package ID Orig. computer Test computer
NESC9839/01 DEC VAX 11/780 DEC VAX 8810
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3. DESCRIPTION OF PROGRAM OR FUNCTION

PDES performs the National Bureau of Standards FIPS Pub. 46 data encryption/descryption algorithm used for the cryptographic protection of computer data. The DES algorithm is designed to encipher and decipher blocks of data consisting of 64 bits under control of a 64-bit key. The key is generated in such a way that each of the 56 bits used directly by the algorithm are random and the remaining 8 error-detecting bits are set to make the parity of each 8-bit byte of the key odd, i. e.  there is an odd number of "1" bits in each 8-bit byte. Each member of a group of authorized users of encrypted computer data must have  the key that was used to encipher the data in order to use it. Data  can be recovered from cipher only by using exactly the same key used to encipher it, but with the schedule of addressing the key bits altered so that the deciphering process is the reverse of the enciphering process. A block of data to be enciphered is subjected to an initial permutation, then to a complex key-dependent computation, and finally to a permutation which is the inverse of the initial permutation.
Two PDES routines are included; both perform the same calculation. One, identified as FDES.MAR, is designed to achieve speed in execution, while the other identified as PDES.MAR, presents a clearer view of how the algorithm is executed.
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4. METHOD OF SOLUTION:
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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:
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6. TYPICAL RUNNING TIME:
NESC9839/01
A little test program has been written to test encryption/decryption.
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7. UNUSUAL FEATURES OF THE PROGRAM:
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8. RELATED AND AUXILIARY PROGRAMS:
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9. STATUS
Package ID Status date Status
NESC9839/01 26-MAR-1991 Tested at NEADB
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10. REFERENCES

U. S. Department of Commerce,
             National Bureau of Standards,
             Federal Information Processing Standards
             Publication 46, January 15, 1977.
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11. MACHINE REQUIREMENTS:
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12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NESC9839/01 VAX-11 MACRO
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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  VMS.
NESC9839/01
VMS 5.3 (VAX 8810).
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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:
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15. NAME AND ESTABLISHMENT OF AUTHORS

             D. N. Nessett
             Lawrence Livermore National Laboratory
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16. MATERIAL AVAILABLE
NESC9839/01
File name File description Records
NESC9839_01.001 Information file 73
NESC9839_01.002 Command file to run the code 10
NESC9839_01.003 Main source program 24
NESC9839_01.004 Macro file for faster execution 1593
NESC9839_01.005 Macro file for clear view prog. algorithm 550
NESC9839_01.006 Output of test problem 7
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17. CATEGORIES
  • P. General Mathematical and Computing System Routines

Keywords: computer networks, dec computers, security, standards.