Article View: sci.crypt
Article #2112Re: Chosen crypto-text attack on RSA
From: Thomas Grant Edwards
Date: Sun, 13 Dec 1992 15:04
Date: Sun, 13 Dec 1992 15:04
15 lines
1220 bytes
1220 bytes
In article <YSN9FVS@minnie.zdv.uni-mainz.de> pom@anke.imsd.uni-mainz.DE (Prof. Dr. Klaus Pommerening) writes:
>Assume Alice has sent an encrypted message c, and Charles
>(the eavesdropper) has got c and wants to know the
>corresponding plaintext m. Let n be Alice's public
>modulus, e the public exponent, and d the private exponent
>(assume c < n); then m = c^d mod n.
>2. Charles gets Alice to decrypt y (or to sign y, if the same
> keys are used for signature). He gets u = y^d mod n.
>3. Now Charles calculates
> tu mod n = x^{-d}*y^d mod n = x^{-d}*x^d*c^d mod n = m.
>Never sign a document that Charles presents to you!
I wonder if PGP 2.2 will have this analysis feature!
-Thomas
Technical Details
Message-ID:
<1992Dec13.150444.8941@src.umd.edu>Path:
arc1-ca.pugleaf.net!sparky!uunet!spool.mu.edu!darwin.sura.net!mojo.eng.umd.edu!disney.src.umd.edu!tedwardsReferences:
<1992Dec4.102242.25130@extropia.wimsey.bc.ca> <YSN9FVS@minnie.zdv.uni-mainz.de>Show Full Headers
Complete Article Headers
Newsgroups: sci.crypt Path: arc1-ca.pugleaf.net!sparky!uunet!spool.mu.edu!darwin.sura.net!mojo.eng.umd.edu!disney.src.umd.edu!tedwards From: tedwards@eng.umd.edu (Thomas Grant Edwards) Subject: Re: Chosen crypto-text attack on RSA Message-ID: <1992Dec13.150444.8941@src.umd.edu> Sender: news@src.umd.edu (C-News) Organization: Project GLUE, University of Maryland, College Park References: <1992Dec4.102242.25130@extropia.wimsey.bc.ca> <YSN9FVS@minnie.zdv.uni-mainz.de> Date: Sun, 13 Dec 1992 15:04:44 GMT Lines: 17