How effective is open source crypto?

[Anne & Lynn Wheeler]

having worked on some of the early e-commerce/certificate stuff ... recent ref:
http://www.garlic.com/~lynn/aadsm13.htm#25 Certificate Policies (addenda)

the assertion is that basic ssl domain name certificate is so that the 
browser can check the domain name from the url typed in against the domain 
name from the presented (trusted) certificate ... and have some confidence 
that the browser is really talking to the server that it thinks it is 
talking to (based on some trust in the issuing certification authority). in 
that context ... self-certification is somewhat superfluous ... if you 
trust the site to be who they claim to be ... then you shouldn't even have 
to bother to check. that eliminates having to have a certificate at all ... 
just transmit a public key

so slight step up from MITM-attacks with self-signed certificates would be 
to register your public key at the same time you register the domain. 
browsers get the server's public key from dns at the same time it gets the 
ip-address (dns already supports binding of generalized information to 
domain ... more than simple ip-address). this is my long, repetitive 
argument about ssl domain name certification ....
http://www.garlic.com/~lynn/subpubkey.html#sslcerts

i believe a lot of the non-commercial sites have forgone SSL certificates 
.... because of the cost and bother.

some number of the commercial sites that utilize SSL certificates .... only 
do it as part of financial transaction (and lots of them .... when it is 
time to "check-out" .... actually transfer to a 3rd party service site that 
specializes in SSL encruyption and payments). The claim by many for some 
time .... is that given the same exact hardware .... they can do 5-6 times 
as many non-SSL (non-encrypted) HTTP transactions as they can do SSL 
(encrypted) HTTPS transactions .... aka they claim 80 to 90 percent hit to 
the number of transactions that can be done switching from HTTP to HTTPS.


a short version of the SSL server domain name certificate is worry about 
attacks on the domain name infrastructure that can route somebody to a 
different server. so SSL certificate is checked against to see if the 
browser is likely talking to the server they think they are talking to. the 
problem is that if somebody applies for a SSL server domain name 
certificate .... the CA (certification authority) has to check with the 
authoritative agency for domain names .... to validate the applicants 
domain name ownership. The authoritative agency for domain names is the 
domain name infrastructure that has all the integrity concerns giving rise 
for the need for SSL domain name certificates. So there is a proposal for 
improving the integrity of the domain name infrastructure (in part backed 
by the CA industry ... since the CA industry is dependent on the integrity 
of the domain name infrastructure for the integrity of the certificate of 
the certificates) which includes somebody registering a public key at the 
same time at a domain name. So we are in catch-22 ....

1) improving the overall integrity of the domain name infrastructure 
mitigates a lot of the justification for having SSL domain name 
certificates (sort of a catch-22 for the CA industry).

2) registering a public key at the same time as domain name infrastructure 
... implies that the public key can be served up from the domain name 
infrastructure (at the same time as the ip-address .... eliminating all 
need for certificates).

There is a description of doing an SSL transaction in single round trip. 
The browser contacts the domain name system and gets back in single 
transmission the 1) public key, 2) preferred server SSL parameters, 3) 
ip-address. The browser selects the SSL parameters, generates a random 
secret key, encrypts the HTTP request with the random secret key, encrypts 
the random secret key with the public key ... and sends off the whole thing 
in a single transmission .... eliminating all of the SSL protocol 
back&forth setup chatter. The browser had to contact the domain name system 
in any case to get the ip-address .... the change allows the browser to get 
back the rest of the information in the same transmission.




--
Anne & Lynn Wheeler    http://www.garlic.com/~lynn/
Internet trivia 20th anv http://www.garlic.com/~lynn/rfcietff.htm
  


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