From 2d3de78ad61f2118c653c41ecac184f8591d4d46 Mon Sep 17 00:00:00 2001 From: mdw Date: Wed, 21 Feb 2001 20:45:53 +0000 Subject: [PATCH] Describe recently-added hash functions. --- hashsum.1 | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/hashsum.1 b/hashsum.1 index 96e19ae..8e8c475 100644 --- a/hashsum.1 +++ b/hashsum.1 @@ -201,6 +201,13 @@ The .B hashsum program understands several hashing algorithms: .TP +.BR md2 +Designed by Ron Rivest, although I don't know when, and described in +RFC1319, MD2 is a really old and slow hash function. Its security is +suspect too: only its checksum stands between it and collision-finding +attacks. Use of MD2 is not recommended, though it's still used in +various standards. +.TP .BR md4 " and " md5 Designed by Ron Rivest in 1990 and 1992 respectively and described in RFCs 1186, 1320 and 1321, these two early hash functions are efficient @@ -231,11 +238,16 @@ drop-in replacement for MD4, MD5 and the old RIPEMD. The 256 and .B tiger Designed by Ross Anderson and Eli Biham to take advantage of 64-bit processors, Tiger seems to be an efficient and strong hash function. -Its 192-bit output is wider than that of any other algorithm supported -by -.BR hashsum . It's a relatively new algorithm, however, and should probably be approached with an open-minded caution. +.TP +.B sha256 ", " sha384 " and " sha512 +Designed by the US National Security Agency to provide security +commensurate with the Advanced Encryption Standard, these hash functions +provide long outputs. SHA-256 is fairly quick, though the longer +variants are slower on 32-bit hardware since they require 64-bit +arithmetic. They're all very new at the moment, and should be +approached with an open-minded caution. .PP The default hashing algorithm is determined by looking at the name by which it was invoked passed to it in -- 2.11.0