Attacks on PGP

Things are heating up between Fred Cohen and some of the rest of the list.

I don't believe MIT is in collusion with the NSA or any other government
agency to deliberately weaken or cripple PGP. I base this on having dealt
with some of the MIT folks, with the various source code analyses folks
have done, etc.

However, I think it's a perfectly *fine* idea for some group to launch a
cryptanalytic attack on PGP, or an attack based on any other approaches.
This is the "tiger team," or "Team B" approach to finding flaws and
weaknesses.

I don't take the security of PGP only on faith, though analyzing it is not
my bag, as they say. Rather, I use the Popper/Bartley notions of
falsifiabilty and see truth as a process, not a state. Seeing lots of
source code available, independent compilations on various machines, and
believing neither Zimmermann nor Atkins nor Schiller, etc., would consent
to inserting back doors into PGP, I am thus led to _believe_ that PGP is
probably not so affected. Doesn't mean it isn't so, but I'm not overly
worried about it.

Still, more studies and technical attacks (technical, not verbal) would be
welcome.

One of the problems we in the "civilian cryptography" sector face is that
we don't have much activity in cryptanalysis. (We've talked about this
several times before, before Fred Cohen joined the list, for example.) The
NSA and other intelligence agencies have not only code makers, they also
have code _breakers_ (such as modern ciphers are breakable, which hasn't
been the case much lately, if Bamford and Kahn are to be believed).
Probably entire groups whose only job is to try to break the systems
devised by others. (Modern ciphers are not as prone to breakage as earlier
ciphers were, for technical reasons, so I suspect the number of
cryptanalysts has shrunk since the good old days when they had more
successes...there may only be a small contingent left...)

The lack of cryptanalysis papers at "Crypto" has been striking...I was told
that the program committee considers cryptanalysis to be less important
than original research. (I can see the rationale in this, as Crypto is an
academic/research conference, and there are really no "engineering" crypto
conferences. And cryptanalysis might not even fit into an engineering
conference very well, as cryptanalysis is traditionally a sort of
"hobbyist" activity--if you've read Kahn you'll know what I mean.)

Crypto comes in various flavors, from hardware implementations, to number
theory, to Unix/IETF sorts of standards, to digital cash, and even to
statistical analysis. It is dangerous to have a "monoculture" in which one
topic is the trendy one and everyone is urged to work on that (whether the
"that" is PGP or Java or anything else equally trendy).

Most of the activity has been on adding hooks to PGP to make it usable in
other programs, or on remailers. Not as much effort has gone into proofs of
validity, systems analysis, etc. (Eric Hughes and I talked about this
several years ago, before the Cypherpunks group was formed...the need for
"Viper"-like systems with provably correct components, especially for
digital money, etc.)

If folks think PGP is flawed, or deserves an independent and critical look,
then this is a good project for someone. (I think several such analyses
have been made, however...this doesn't make it impossible for a flaw or
backdoor to exist, but at least the code has been examined by various
folks. I'm personally not too worried, though this has little suasive
value.)

(The Monoculture of Trendy Projects. My own programming mini-project, while
proceeding slowly, is of a pattern extractor and "entropy estimator" for
text. Stuff like measuring patterns, examining clusterings and
author-specific patterns. I'm writing it as a bunch of "critic agents" who
are responsible for different areas of analysis. In SmalltalkAgents. My
point? There will be those who cite the "monoculture" and scoff at anything
not written in C++ for Unix boxes, or not built to be Net-aware from the
gitgo, or not written as applets in Java....oh well, in Digital Walden, one
marches to a different drummer. Better to program the thing I _want_ to
program rather than the things I _don't_ want to program, and hence
_won't_. Final note: it'll be ready for use and maybe demonstration when
it's ready. And ready when it's finished, finished when it's ready.)

I've long appreciated Fred Cohen's work on viruses, so it's nice to have
him on the Cypherpunks list. Maybe Fred can tell us if it's really true
that he was stopped by U.S. Customs and held for many hours at the Canadian
border when going to or returning from a conference where he described
computer viruses....

--Tim May

..........................................................................
Timothy C. May         | Crypto Anarchy: encryption, digital money,
tcmay@sensemedia.net   | anonymous networks, digital pseudonyms, zero
408-728-0152           | knowledge, reputations, information markets,
Corralitos, CA         | black markets, collapse of governments.
Higher Power: 2^756839 | Public Key: PGP and MailSafe available.
"National borders are just speed bumps on the information superhighway."

[good comments deleted]

>The lack of cryptanalysis papers at "Crypto" has been striking...I was told
>that the program committee considers cryptanalysis to be less important
>than original research. (I can see the rationale in this, as Crypto is an
>academic/research conference, and there are really no "engineering" crypto
>conferences. And cryptanalysis might not even fit into an engineering
>conference very well, as cryptanalysis is traditionally a sort of
>"hobbyist" activity--if you've read Kahn you'll know what I mean.)

Tim,

My impression (based on reviewing papers for the last few CRYPTOs and
EUROCRYPTs) is that the reason for the lack of "practical" papers is
primarily that not very many of them get submitted.  In fact, I think
there actually are a fair number of cryptanalysis papers at CRYPTO,
at least compared with the even smaller number of papers there that
describe new ciphers.  Anyway, cryptanalysis IS part of the mainstream
of the academic crypto world these days (consider differential
cryptanalysis, linear cryptanalysis, etc.)

-matt

> Maybe Fred can tell us if it's really true
> that he was stopped by U.S. Customs and held for many hours at the Canadian
> border when going to or returning from a conference where he described
> computer viruses....

Not for many hours, but we had an interesting non-discussion, and there
was a really thorough search of my bags (every piece of paper was
individually examined in great detail and a guard was subtly added to
the other side of the line).  They looked at every slide, checked out
the bags themselves for secret compartments, but the one thing they
didn't do was check the contrnts of my floppy disks.  Istn't technology
wonderful?

-- 
-> See: Info-Sec Heaven at URL http://all.net
Management Analytics - 216-686-0090 - PO Box 1480, Hudson, OH 44236

On Jul 31, 11:51pm, Dr. Frederick B. Cohen wrote of his experiences at
the Canada-USA border:
>  They looked at every slide, checked out
> the bags themselves for secret compartments, but the one thing they
> didn't do was check the contrnts of my floppy disks.  Istn't technology
> wonderful?

Until a few years ago, carrying software across the border from the states
to Canada, one would only pay duty on the value of the media. Canadian
Customs regulations did not recognise any value in the information
contained on the floppies. I haven't actively exported/imported software
in this manner recently (well, I carried 2.6ui to Mobile and back without
realising it (or, indeed, ever putting it in a drive) and so broke ITAR)
so I'm not sure how things stand currently.

I think they might actually have been convinced of the value of software.
[Department of External Affairs and International Trade has been, as noted
earlier. Danger of software, at least.]

frodo =)

-- 
Richard Martin 
Alias|Wavefront - Toronto Office [Co-op Software Developer, Games Team]
rmartin@alias.com/g4frodo@cdf.toronto.edu       http://www.io.org/~samwise
Trinity College UofT ChemPhysCompSci 9T7+PEY=9T8 Shad Valley Waterloo 1992

On Tue, 1 Aug 1995, Richard Martin wrote:

> Until a few years ago, carrying software across the border from the states
> to Canada, one would only pay duty on the value of the media. Canadian
> Customs regulations did not recognise any value in the information
> contained on the floppies. I haven't actively exported/imported software
> in this manner recently (well, I carried 2.6ui to Mobile and back without
> realising it (or, indeed, ever putting it in a drive) and so broke ITAR)
> so I'm not sure how things stand currently.
> 
> I think they might actually have been convinced of the value of software.
> [Department of External Affairs and International Trade has been, as noted
> earlier. Danger of software, at least.]


As far as I know, under current GATT regulations software is not
considered a commodity, and therefore its import does not attract customs
duties. However, I'm not sure about the actual behaviour of the US
customs; from recent cases I can confirm that in the European Union and
South Africa that rule is respected.

Timothy C. May writes:
> Things are heating up between Fred Cohen and some of the rest of the list.

Were it not for the fact that others are doing the job better than I,
I'd be compelled to enter into the fray myself...

> I've long appreciated Fred Cohen's work on viruses,

And frankly, I've long been forced to install filtering on virtually
every list "Dr." Cohen shows up on. He rarely has much of value to say
-- he also frequently gets kicked off of mailing lists for being a wee
bit to explicit in the advertising hype for his services he puts up on
virtually every mailing list he enters -- be it firewalls, bugtraq, or
whatever.

I considered, as I said, entering this fray early. Fortunately, "Dr."
Cohen has managed to demonstrate his capacity to alienate without my
having to warn anyone about it in advance.

This is not to say that I think PGP couldn't use enhances scrutiny, or
that all of "Dr." Cohen's comments are always completely meritless.
However, "Dr." Cohen rarely enhances the conversations he's a part of.

Perry

PS I'm sure he has a real PhD. Its just that the other couple dozen
PhDs on this mailing list don't seem to insist on rubbing it in
people's noses constantly -- ditto for all other mailing lists I've
seen him on.