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From: smb@ulysses.att.com (Steven Bellovin)
Newsgroups: sci.military
Subject: Re: IFF
Message-ID: <1991Jan25.032524.11662@cbnews.att.com>
Date: 25 Jan 91 03:25:24 GMT
References: <1991Jan19.041005.4675@cbnews.att.com>
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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.