RFC 1810 (rfc1810) - Page 2 of 7
Report on MD5 Performance
Alternative Format: Original Text Document
RFC 1810 Report on MD5 Performance June 1995 Measurements The performance of MD5 was measured. The code was an optimized version of the MD5 reference implementation from the RFC [3], and is available for anonymous FTP [7]. The following are the results of the performance test "md5 -t", modified to prohibit on-chip caching of the data block: 87 Mbps DEC Alpha (190 Mhz) 33 Mbps HP 9000/720 48 Mbps IBM RS/6000 7006 (PPC 601 @80 Mhz) 31 Mbps Intel i486/66 NetBSD 44 Mbps Intel Pentium/90 NeXTStep 52 Mbps SGI/IP-20 IRIX 5.2 37 Mbps Sun SPARC-10/51, SPARC-20/50 SunOS 4.1.3 57 Mbps Sun SPARC-20/71 SunOS 4.1.3 These rates do not keep up with currently available IP bandwidth, e.g., 100 Mbps TCP and 130 Mbps UDP over a Fore SBA-200 ATM host interface in a Sun SPARC-20/71. Values as high as 100 Mbps have been reported for the DEC Alpha (190 Mhz). These values reflect on-chip caching of the data. It is not clear at this time whether in-memory, off-chip cache, or on-chip cache performance measures are more relevant to IP performance. Analysis of the MD5 Algorithm The MD5 algorithm is a block-chained hashing algorithm. The first block is hashed with an initial seed, resulting in a hash. The hash is summed with the seed, and that result becomes the seed for the next block. When the last block is computed, it's "next-seed' value becomes the hash for the entire stream. Thus, the seed for block depends on both the hash and the seed of its preceding block. As a result, blocks cannot be hashed in parallel. Each 16-word (64-byte) block is hashed via 64 basic steps, using a 4-word intermediate hash, and collapsing the intermediate hash at the end. The 64 steps are 16 groups of 4 steps, one step per intermediate hash word. This RFC uses the following notation (as from RFC-1321 [3]): A,B,C,D intermediate hash words X[i] input data block T[i] sine table lookup << i rotate i bits F logical functions of 3 args Touch Informational
