Re: LEAP Security Vulnerabilities??
In message [EMAIL PROTECTED], Richard A Steenberge n writes: On Thu, Jun 13, 2002 at 02:34:29PM -0500, Stephen Sprunk wrote: WEP's only real failure was the failure to specify keying; vendors (and users) with less security experience interpreted this to mean static keys were sufficient. The choice of RC4 was unfortunate given the above problem, but the coming switch to AES should fix that. Most existing wireless APs cannot keep up with 802.11b doing RC4 (which is EXTREMELY light on the cpu) at line rate. RC4 if used properly is light-weight. 802.11 is employing it in an unnatural environment, and that causes trouble, including performance issues. More specifically -- RC4 is a stream cipher, which means that it must be employed over a reliable underlying data stream. It's perfect above TCP, for example. But 802.11 is a packet environment, with no underlying stream. Accordingly, the base RC4 key -- 40 bits or 112 bits -- is combined with a 24-bit number (sometimes a counter, sometimes random, but in either case sent in the clear in the packet) to form an actual RC4 key that's used to encrypt just a single packet. The problem is that key setup is roughly as expensive as encrypting 300 bytes or thereabouts. So all those 40-byte TCP ACK packets are a lot more expensive for crypto processing than they should be. --Steve Bellovin, http://www.research.att.com/~smb (me) http://www.wilyhacker.com (Firewalls book)
LEAP Security Vulnerabilities??
Title: LEAP Security Vulnerabilities?? I am well aware of the many security vulnerabilities that exist on wireless networks as well as the inadequacies of WEP. I was curious if anyone has had any experiences with Cisco's LEAP authentication protocol? I have scoured the net for reviews or documents examining any potential vulnerabilities, but have not been able to find any. Any and all help or information would be appreciated. Thanks in advance, Jason Hyska Worldwide Information Security Johnson Johnson [EMAIL PROTECTED]
RE: LEAP Security Vulnerabilities??
Title: LEAP Security Vulnerabilities?? If you're serious enough about security to find 128 WEP inadequate, I would think you would be doing some sort of VPN or other SSL solution anyway, making WEP redundant. Or am I missing something? Best, -Al Rowland -Original Message-From: Hyska, Jason [JJCUS] [mailto:[EMAIL PROTECTED]]Sent: Thursday, June 13, 2002 10:15 AMTo: [EMAIL PROTECTED]Subject: LEAP Security Vulnerabilities?? I am well aware of the many security vulnerabilities that exist on wireless networks as well as the inadequacies of WEP. I was curious if anyone has had any experiences with Cisco's LEAP authentication protocol? I have scoured the net for reviews or documents examining any potential vulnerabilities, but have not been able to find any. Any and all help or information would be appreciated. Thanks in advance, Jason Hyska Worldwide Information Security Johnson Johnson [EMAIL PROTECTED]
Re: LEAP Security Vulnerabilities??
Thus spake Hyska, Jason [JJCUS] [EMAIL PROTECTED] I am well aware of the many security vulnerabilities that exist on wireless networks as well as the inadequacies of WEP. WEP's only real failure was the failure to specify keying; vendors (and users) with less security experience interpreted this to mean static keys were sufficient. The choice of RC4 was unfortunate given the above problem, but the coming switch to AES should fix that. I was curious if anyone has had any experiences with Cisco's LEAP authentication protocol? I have scoured the net for reviews or documents examining any potential vulnerabilities, but have not been able to find any. Any and all help or information would be appreciated. LEAP itself is unlikely to present problems, as it's just a means to verify 802.1x credentials and force key rotation. I'd be much more wary of potential problems in 802.1x itself, since that's the over-the-air portion. S
Re: LEAP Security Vulnerabilities??
On Thu, Jun 13, 2002 at 02:34:29PM -0500, Stephen Sprunk wrote: WEP's only real failure was the failure to specify keying; vendors (and users) with less security experience interpreted this to mean static keys were sufficient. The choice of RC4 was unfortunate given the above problem, but the coming switch to AES should fix that. Most existing wireless APs cannot keep up with 802.11b doing RC4 (which is EXTREMELY light on the cpu) at line rate. I'm afraid to see what they consider acceptable for AES, anything done as a firmware upgrade is going to be quite limiting. At least for 802.11a I believe they're doing better. -- Richard A Steenbergen [EMAIL PROTECTED] http://www.e-gerbil.net/ras PGP Key ID: 0x138EA177 (67 29 D7 BC E8 18 3E DA B2 46 B3 D8 14 36 FE B6)
Re: LEAP Security Vulnerabilities??
Thus spake Richard A Steenbergen [EMAIL PROTECTED] On Thu, Jun 13, 2002 at 02:34:29PM -0500, Stephen Sprunk wrote: The choice of RC4 was unfortunate given the above problem, but the coming switch to AES should fix that. Most existing wireless APs cannot keep up with 802.11b doing RC4 (which is EXTREMELY light on the cpu) at line rate. I'm afraid to see what they consider acceptable for AES, anything done as a firmware upgrade is going to be quite limiting. At least for 802.11a I believe they're doing better. Most vendors chose to do their RC4 encryption in software and consequently can't do more than 1-2mb/s -- caveat emptor. That's hardly a failing of the 802.11 WG; at least one vendor can do RC4 (and soon AES) at wire rate. You can have it good, fast, or cheap -- pick two. S
