From: trollins@debbie.telos.com (Tom Rollins)
Date: Wed, 29 Jun 94 05:28:49 PDT
Subject: Un-Documented Feature
Message-ID: <9406291228.AA21293@debbie.telos.com>
MIME-Version: 1.0
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PGP 2.6ui has an undocumented feature.

When generating a Public/Secret key pair PGP documentaion shows
the command "pgp -kg" as the way to generate the keys.
I had posted about how pgp uses a small public key exponent
of 17 which is 5 bits.
It turns out that this is only the default setting.
An Un-Documented feature in PGP 2.6ui (I don't know about other
versions as I don't have source code for them) lets you specify
the number of bits in your public key exponent.
The command "pgp -kg keybits ebits" will let you specify this
public key exponent size. For example "pgp -kg 1024 256" will
generate a key with modulus of aprox 1024 bits and a public
key exponent of 256 bits rather than the 5 bit default.

Too Bad pgp doesn't let you look at the public key exponent.
I had to write some code to see them.

					-tom