Comments on binding cryptography (1)

["Bert-Jaap Koops" <E.J.Koops@kub.nl>]

Apologies for not reacting earlier; I have been away for six days.
I found many reactions to the posting on binding cryptograhpy 
in my mail box, which I have read with interest. 
Here are my comments, excuse me if they are lengthy.

First and foremost, I want to stress that the proposal primarily 
addresses the issue of providing information security. It does not 
want to solve the problem of criminals using encryption.

I hope the following analogy may clear this (but please don't stretch
the analogy too far).
The government wants to offer citizens good transport, so they make 
public roads. Because some citizens endanger others through drunk 
driving, the government makes the rule that if you want to drive a 
car, you must be sober. If you want to drive on the public road, fine, don't 
drink. If you want to drink, fine, take a bike or cab or use public 
transport.

Now, the binding cryptography proposal wants to provide law-abiding 
citizens with good crypto. (I'm currently not using any, because I 
don't have an easy to use and reliable system.) A government may 
establish an infrastructure for good crypto (like the public roads), 
with the requirement that you keep to the "binding" rule (like "don't 
drive drunk"). If you don't want to use the binding cryptography, 
fine, use another system (take a bike or cab). The system will not 
prevent criminals from using cryptography - it isn't meant to. 
Yes, criminals can use superencryption or other (mutually agreed upon) 
ways to use the system and yet be out of law-enforcement's reach, 
but they might as well use PGP in the first place. I do not want to see PGP 
outlawed, and I do not want to have PGP use be regarded as 
suspicious (just as I don't think it is suspicious if you take a cab 
late at night). Setting up a good information security structure can 
very well be compatible with having other means of information 
security. 

You ask why should the government offer good crypto, when it's 
already available? I think that cypherpunks are not average - they 
know about crypto and they can use it. The majority of the citizens, 
however, do not use crypto, because they don't understand it and 
because there's no easy-to-use and reliable standard. If the 
government were to offer this, it would make a difference to many 
people.

Then, you say, it affects my privacy. As far as I see it, it does 
not. The binding cryptography system allows regular monitoring for 
compliance (like road police checking whether people are sober). It 
does not involve reading of messages. The only time messages are read 
is when law-enforcement agencies (LEAs) have a warrant and ask a TRP 
to hand over a session key. This is not fundamentally different from the 
present situation, where LEAs can wiretap with a warrant. Privacy 
will be protected more or less to the same extent as presently.

If you don't agree with governments having the possibility of 
intercepting communications anyway, OK, that's your opinion. I have 
another opinion, and we needn't discuss further - this is not the 
issue.

Then, if you say you don't trust your government, OK, I can see a 
point. Generally, I notice a difference between US and Europe in our 
views on the role of governments. That is legitimate, and something 
for each to discuss domestically. 
(Yes, Alex, IRT-gate is a good point, but at least it has led to a critical 
investigation by parliament and a more critical attitude with our 
judges in judging investigation methods.)
(And Allen, if binding cryptography helps totalitarian governments in 
arbitrarily monitoring all communications, I oppose this. China uses 
video cameras in Lhasa to monitor potential demonstrations of Tibetans. 
I oppose this, and I blame the Chinese government for it, not the 
inventor of video cameras.)

I feel at least that allowing TRPs to decrypt single communications 
if the LEA has a court warrant is better protection than escrowing my 
private key with the government. Also, choosing your own TRP allows 
you better protection than having to use a government-chosen one. On 
the other hand, I think there should be some regulation on TRPs, if 
only to address liability issues. I think a government certification 
of TRPs would not be a bad thing, if this is done in an open, 
flexible and preferably independent way - for instance a 
semi-govenmental "TRP approving authority" (the same way we have data 
protection authorities who monitor compliance with data protection 
legislation). Again, we may have different opinions on this given the 
difference between US and Europe.

Someone pointed out that a TRP could be corrupted and collaborate 
with the law-enforcement agencies. Then, all sessions would be read 
by the LEA. Indeed, this is a threat to be taken into account. At 
least the binding alternative is better protection against 
collaborating TRPs than key-escrow, as at least it leaves 
communications from before the corruption unharmed. Moreover, the 
system allow easy change of TRP, so the moment you notice something 
weird about this TRP, you choose another one. It's really a matter of 
trust.

Finally, I get the impression that some cypherpunks feel the 
law-enforcement problem to be a problem of "them" as opposed to us. I 
- and this is my personal opinion - feel it is "my" problem as well. 
I live in a society with which I am generally satisfied, not the 
least because we have a rule of law. Tracing criminals is my concern 
as well. I am not happy that, in some ways, I have to give up some 
freedom, but I think it is worth while. I would not mind using a 
government-offered crypto system that uses binding cryptography. All 
I want is that it is a good system and I want to be sure I trust my TRP.
I would prefer it if no such system were needed, but if it helps in 
protecting me from criminals, I can live with it.

Bert-Jaap

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Bert-Jaap Koops                         tel     +31 13 466 8101
Center for Law, Administration and      facs    +31 13 466 8149
Informatization, Tilburg University     e-mail  E.J.Koops@kub.nl
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