From: Lee Tien <tien@well.sf.ca.us>
Date: Wed, 26 Jan 94 13:12:08 PST
To: franz@cs.ucdavis.edu
Subject: Re:  Crypto and 4th A.
Message-ID: <199401262108.NAA09371@well.sf.ca.us>
MIME-Version: 1.0
Content-Type: text/plain



Roy:  I'm a lawyer, and I've not run across any law review articles 
that discuss cryptography in relation to privacy or Fourth 
Amendment rights.  

The classic treatise on Fourth Amendment search and seizure is by 
LaFave.  I haven't looked at it recently, but it might discuss crypto.  

One "brute-force" approach to the legal literature is to go to the 
law library and scan the Index to Legal Periodicals, which is 
organized by subject as well as author.  I don't think you'll find 
anything under crypto, but you'll find LOTS of stuff about the 
Fourth Amendment.  It'll take time, but by scanning the titles of 
the articles you'll be able to tell if there's anything about crypto.  

Some law libraries also have an index of recent articles on CD-
ROM, which is easier to search but is typically less 
comprehensive.

Also check under the name Tribe, L.  Tribe is the nation's leading 
constitutional scholar IMHO and at the first Conference on 
Computers, Freedom and Privacy he gave a talk on "technology 
and the Constitution."  I don't recall his talking about crypto at all, 
but he did use as an example the cases involving privacy and 
wiretapping, i.e., Olmstead v. U.S., Katz v. U.S.

Katz is the case which set forth the notion of "reasonable 
expectation of privacy."  (REP)  Tribe was a Supreme Court clerk 
who worked on this opinion, I believe.

Tribe's one-volume treatise, "American Constitutional Law," 
briefly discusses constitutional dimensions of privacy law in one 
section.  It is good, but only current up to 1988, as I recall.

Having said that, it becomes obvious that you may want to focus 
on the law of REP and how it intersects with technological change.  
For instance, advocates of Digital Telephony, Clipper et al often 
make the argument that "we're only trying to maintain the status 
quo -- we just want to keep the existing practical balance that 
comes from most communications being plaintext."

Yet in the same discussion -- almost in the same breath -- the same 
advocates of "maintaining the status quo" will remind you that you 
have NO REP in such things as your hair fibers, DNA obtained 
from saliva under a postage stamp, etc., and therefore "we don't 
need a search warrant."  

Clearly, forensic technologies have improved greatly over the 
years, but the law has not consistently followed a "status quo" 
approach.  Law enforcement is better described as having a 
"ratchet" approach; they want to keep all the gains from 
improvements in forensic and surveillance technology, but not the 
losses.  (I am indebted to Mike Godwin of EFF for this point, 
which he made publicly in a panel with an Assistant U.S. Attorney 
back in January.)

BTW, keep in mind that there's an (arguably) crucial difference 
between the privacy implications of something like hair fiber or 
DNA forensic analysis and encryption/decryption relative to 
communications.  Analyzing my hair fibers reveals no information 
about anyone else.  With most communications there is a threat to 
the privacy of more than one person.  

I'm curious -- what's the thesis or general thrust of your article?  

I could say more, but that's probably enough for now.  We can take 
this discussion to e-mail rather than the list if Cypherpunks find it 
too tangential.  

Lee Tien
tien@well.sf.ca.us