On Mon, 6 Dec 1999, John Harleman wrote: > triple des can support two key sizes--two key or three key. 2key triple > des=112-bits of symmetric strength, 3key triple des=168-bits. IPSEC uses only the 3-key form, which has only 112 bits of strength against meet-in-the-middle attacks. Henry Spencer henry@spsystems.net (henry@zoo.toronto.edu)