$OpenBSD: patch-src_zrtp_c,v 1.2 2013/12/19 10:13:45 zhuk Exp $
--- src/zrtp.c.orig	Mon Nov 25 13:20:20 2013
+++ src/zrtp.c	Mon Nov 25 13:25:41 2013
@@ -771,7 +771,11 @@ static OrtpZrtpContext* createUserData(ZrtpContext *co
 	userData->zrtpContext=context;
 	userData->timerWillTriggerAt=0;
 	userData->last_recv_zrtp_seq_number=0;
+#ifdef HAVE_ARC4RANDOM
+	userData->last_sent_zrtp_seq_number=arc4random_uniform(0xffff) + 1;
+#else
 	userData->last_sent_zrtp_seq_number=rand()+1; // INT_MAX+1 (signed)
+#endif
 
 	userData->srtpRecv=NULL;
 	userData->srtpSend=NULL;
