letovsky-stanley@yale.UUCP (05/19/88)
From: Stanley Letovsky <letovsky-stanley>
Re: Atul Butte's proposal for "tamper-proof packaging" for
software to prevent dissemination of software viruses
(Comp.sys.mac Sun, 08 May 88):
Butte proposes a variation on the one-way encryption functions of
public key cryptography schemes which could encrypt software in a way
that ensures that the software actually came straight from the vendor.
He also suggests that the decryption key could somehow be provided along
with the encrypted software. His proposal is interesting, and seems
viable in its overall framework, but one detail is problematic. One
cannot distribute the decryption key with the encrypted software: any
evil hacker could create such a package, encrypting virus-infected
software and supplying his own key. The decryption keys must be
publicly posted in such a way that the consumer could have absolute
confidence that they belong to a reputable firm, while the firm is
responsible for ensuring that they alone know how to encrypt for their
publicly posted decryption key.
Incidentally, Butte's scheme would seem to have implications for
preventing software bootlegging. The vendor could supply the decryption
key only to customers with proof of purchase. Bootleggers would have to
risk virus infection. Vendors might even be motivated to distribute
infected bootleg copies around the marketplace, so as to heighten demand
for the genuine article. Of course, they could do that even without
tamper-proof packaging...
Stan Letovsky letovsky@yale.edu
David Littman littman-david@yale.edu
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