From owner-freebsd-hardware Mon May 15 23:31:49 2000 Delivered-To: freebsd-hardware@freebsd.org Received: from roam.psg.com (roam.psg.com [147.28.4.2]) by hub.freebsd.org (Postfix) with ESMTP id 8228337BA68 for ; Mon, 15 May 2000 23:31:42 -0700 (PDT) (envelope-from randy@psg.com) Received: from randy by roam.psg.com with local (Exim 3.12 #1) id 12rOvZ-00009V-00; Mon, 15 May 2000 10:45:13 -0700 From: Randy Bush MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Jos Visser Cc: freebsd-hardware@freebsd.org Subject: Re: Wavelan 802.11 with encryption References: <391EF3DE.FA17A058@osp.nl> <391F1A28.41BC7F50@osp.nl> Message-Id: Date: Mon, 15 May 2000 10:45:13 -0700 Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > WEP encryption (default with the Silver Wavelan card) supports a 64-bit > key. actually wep encryption in 802.11 is pretty flawed to begin with. most cards only implement a 40 bit key and given the nature of key management, it will not be changed often. but the real killer is that a 24 bit iv is used to create the per-packet key (in combination with the "permanent" 40 bit key). after 2^24 packets are sent on the network, the rc4 keys will start to be reused. given that rc4 is a pad + xor cipher, this is quite scary. so, while it may be good enough for you, and i am really impressed that you were able to calculate 2^64, it is not good enough for me. and, again, i suggest that it is not good for more than casual use. randy To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message