mark@mips.COM (Mark G. Johnson) (12/07/90)
In article <7685@hub.ucsb.edu> of sci.crypt, David G. Koontz posts a very nice C program that implements the Data Encryption Standard algorithm ("DES") for encryption / decryption of arbitrary files. The program can either encrypt/decrypt using Full DES, or it can bypass the cryptographically-insignificant IP and IP-1 steps, thereby running a lot faster. (IP = Initial Permutation, IP-1 = Inverse Initial Permutation). David supplies a bit of benchmark data: > I measured 33+ kbytes/sec on my IRIS 4D-25/G for Full DES, > and 55+ kbytes/sec for DES without IP and IP-1. It seemed like a fun program to explore, so I measured its performance on several other hardware platforms that happened to be reachable from here. I really wish I had an Acorn machine to measure, also an Olivetti i860 workstation and a NEC SX-3, but I don't. Sorry. A file containing one million bytes ("million") was encrypted as the test case, using the hexadecimal key 0xabcd12345678abcd. The command lines were /bin/time ./des -e -K abcd12345678abcd < million > /dev/null [FULL DES] /bin/time ./des -e -n -K abcd12345678abcd < million > /dev/null [NO IP] Results: MACHINE FULL DES DES WITHOUT IP and IP-1 ========================================================================= MIPS RC6280 82,600 bytes/sec 137,000 bytes/sec MIPS RS3230 Magnum 37,300 bytes/sec 62,500 bytes/sec MIPS M/2000 37,000 bytes/sec 62,100 bytes/sec Sun SPARCstation 1+ 30,800 bytes/sec 49,800 bytes/sec DEC DECstation 3100 24,600 bytes/sec 43,700 bytes/sec Sun SPARCstation 1 24,000 bytes/sec 38,000 bytes/sec MIPS RS2030 23,400 bytes/sec 39,000 bytes/sec Raw data (output of /bin/time) when encrypting 1,000,000 bytes FULL DES DES WITHOUT IP & IP-1 MACHINE REAL USER SYS REAL USER SYS ====================================================================== MIPS RC6280 12.2 12.1 0.0 7.4 7.3 0.0 MIPS RS3230 Magnum 27.6 26.8 0.1 16.4 16.0 0.0 MIPS M/2000 27.1 27.0 0.0 16.2 16.1 0.0 Sun SPARCstation 1+ 32.8 32.5 0.2 20.4 20.1 0.2 DEC DECstation 3100 41.0 40.6 0.3 23.2 22.9 0.2 Sun SPARCstation 1 42.1 41.7 0.2 26.7 26.3 0.2 MIPS RS2030 45.9 42.7 0.3 26.2 25.6 0.2 -- -- Mark Johnson MIPS Computer Systems, 930 E. Arques M/S 2-02, Sunnyvale, CA 94086 (408) 524-8308 mark@mips.com {or ...!decwrl!mips!mark}