jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) (01/19/91)
From: jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) How does IFF on the fighters work? - Jae - << M-1 goes 1/6 mile with 1 gal. My Escort goes 30+ miles with 1 gal. I want to drive an M-1 to school today to solve the parking problem once and all. >> --- Jae@cs.Buffalo.EDU \\// Yes, I am a vi user. But, I know how Jae%cs.Buffalo.EDU@ubvm.BITnet XX to get out of emacs when necessary. V5066R2Z@ubvms.Buffalo.EDU //\\ I only wish there exists xvi. 8-)
jabusch@osiris.cso.uiuc.edu (John Jabusch) (01/24/91)
From: jabusch@osiris.cso.uiuc.edu (John Jabusch) jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) writes: >From: jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) >How does IFF on the fighters work? IFF Transponders automatically sense what mode they're being interrogated in, using a pulse-train timing pattern. Mode determination complete, a reply is formed based on information being fed to the transponder. In the case of Modes 1, 2, and 3a, this is key-punched or thubm-wheeled in by the pilot or ground technician. Mode C (altitude info) usually comes from one of the on-board altimeter systems. Mode 4 (secure mode) is usually handled by a special box which examines the Mode 4 interrogation, and then applies a special algorithm to determine a valid reply. IFF Interrogators will interrogate in any mode selected by the pilot / navigator / tower operator. Mode 4 requires a special box, also, which is used to formulate the interrogation, which only the "crypto" units know how to handle. I provided this as very basic information, since your question was fairly open. -- John W. Jabusch US Army Construction INTERNET: jabusch@cerl.cecer.army.mil Engineering Resesarch Lab MILNET: jabusch@osiris.arpa Champaign, IL "Why waste time learning, when ignorance is instantaneous?" - Hobbes
smb@ulysses.att.com (Steven Bellovin) (01/25/91)
From: smb@ulysses.att.com (Steven Bellovin) In article <1991Jan19.041005.4675@cbnews.att.com>, jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) writes: > From: jae@sybil.cs.Buffalo.EDU (Jae Hoon Lee) > How does IFF on the fighters work? Basically, it's a cryptographic challenge/response. You send some sort of number; the IFF box encodes it using a secret key, and transmits the answer. Your end performs the same encryption, and matches the answers. There are numerous variations possible, including use of timestamps, but that's the basic method.