From d132c65168871d21ad93f2aa96d79fa6223c9943 Mon Sep 17 00:00:00 2001 Message-Id: From: Mark Wooding Date: Sat, 16 Jun 2001 14:06:40 +0000 Subject: [PATCH] Quantify collision probabilities for the stated data volume bounds. Organization: Straylight/Edgeware From: mdw --- keyset.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/keyset.c b/keyset.c index cf041499..27341c00 100644 --- a/keyset.c +++ b/keyset.c @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: keyset.c,v 1.3 2001/02/16 21:39:55 mdw Exp $ + * $Id: keyset.c,v 1.4 2001/06/16 14:06:40 mdw Exp $ * * Handling of symmetric keysets * @@ -29,6 +29,9 @@ /*----- Revision history --------------------------------------------------* * * $Log: keyset.c,v $ + * Revision 1.4 2001/06/16 14:06:40 mdw + * Quantify collision probabilities for the stated data volume bounds. + * * Revision 1.3 2001/02/16 21:39:55 mdw * Major overhaul. Separate functions for manipulating keysets from * functions for manipulating keyset lists. Introduce a concept of @@ -48,6 +51,13 @@ /*----- Tunable parameters ------------------------------------------------*/ +/* --- Note on size limits --- * + * + * For a 64-bit block cipher (e.g., Blowfish), the probability of a collision + * occurring after 32 MB is less than %$2^{-21}$%, and the probability of a + * collision occurring after 64 MB is less than %$2^{-19}$%. + */ + #define T_EXP MIN(60) /* Expiry time for a key */ #define T_REGEN MIN(45) /* Regeneration time for a key */ #define SZ_EXP MEG(64) /* Expiry data size for a key */ -- [mdw]