2022-02-17 22:33:27 -05:00
<!DOCTYPE html>
< html lang = "en" >
< head >
2022-02-18 15:59:12 -05:00
< meta content = "text/html; charset=UTF-8" http-equiv = "content-type" >
< style >
2022-02-17 22:33:27 -05:00
body {
max-width: 30em;
margin-left: 2em;
}
p.center {text-align:center;}
< / style >
2022-02-18 15:59:12 -05:00
< link rel = "shortcut icon" href = "../rho.ico" >
< title > Squaring Zooko’ < / title >
2022-02-17 22:33:27 -05:00
< / head >
< body >
2022-02-18 15:59:12 -05:00
< p > < a href = "./index.html" > To Home page< / a > < / p >
< h1 > Squaring Zooko’ < / h1 >
2022-02-17 22:33:27 -05:00
< p >
Need a system for handing one’ < / p >
< p >
But at the same time the system has to not say, "I can’ ’ < / p >
2022-02-18 15:59:12 -05:00
< p > It seems like the clever bit of CT is the insight that some actions, like
a CA signing a cert, are intended to be public, and so should be forced
(via clever crypto) to take place in public. This makes me wonder what
other crypto actions should also take place in public, in a way that
doesn’ < / p >
< p > Revocation < / p >
< p > Software releases < / p >
< p > Mapping of email address to public key < / p >
< p > Delegation of DNSSEC keys < / p >
< p > < / p >
< p > Of course, globally visible events need to take place at a globally
visible time. The most widely available time is GPS time (which is 19
seconds off the commonly used time), and which is available from the
seldom connected pps line.< / p >
< p > At present, unfortunately, anyone who wants gps time has to do his own
soldering and hack his own software. There is a pre soldered device
available, but it is hard to get. < / p >
< p > < / p >
< p > < / p >
< p >
Imagine skype as originally designed, (central authority maps public and
private keys to user names) plus a key continuity feature, plus the seldom
used option of doing a zero knowledge shared passphrase to detect man in
the middle. < / p >
< p >
The possibility that the zero knowledge check could be used would deter
powerful adversaries, even if seldom used in practice. The more powerful,
the greater the deterrent effect. < / p >
< p >
It is not totally end to end, central authority can listen in, but the
check would limit the amount of listening. < / p >
< p >
It can be made completely end to end for strong passwords. Assume login is
by zero knowledge password protocol, which means that the central
authority does not know the end user’
passwords. < / p >
< p >
The secret key is generated from the strong secret supplied by central
authority, plus the password. < / p >
< p >
When you change your password, you generate a certificate mapping your new
public key to your old public key, which certificate makes other people’
key continuity check happy. < / p >
< p >
If key continuity fails, people get a warning, but they don’
click it away, for that just trains people to click it away. They can just
continue right on and not pay attention to it. < / p >
< p >
Or they could use the zero knowledge shared passphrase procedure to detect
man in the middle. < / p >
< p >
So, if non paranoid, and using easy passwords, works like skype used to
work. No interception except by central authority, and central authority
cannot intercept everyone, or even large numbers of people. < / p >
< p >
If paranoid and using strong passwords, provides OTR like end to end
capability. < / p >
< p > < br / >
< / p >
< p > < br / >
< / p >
< p > Key management is an unsolved problem. In my biased opinion the
best< br / >
solution was my Crypto Kong, which received limited takeup.< br / >
< br / >
So, in conclusion, don’
option for the seriously paranoid.< br / >
< br / >
Instead, autogenerate the keys with zero knowledge passphrase logon.< br / >
< br / >
If he uses a password weak enough to fall to an offline dictionary attack,
this is equivalent to the old skype system, where central authority
manages his keys and he has password logon. If he uses a stronger
password, equivalent to a salted strong passphrase system.< / p >
< p > < / p >
< p > < / p >
< p > < / p >
< p > < / p >
< p > < / p >
< p > < / p >
< p style = "background-color : #ccffcc; font-size:80%" > These documents are
licensed under the < a rel = "license" href = "http://creativecommons.org/licenses/by-sa/3.0/" > Creative
2022-02-17 22:33:27 -05:00
Commons
2022-02-18 15:59:12 -05:00
Attribution-Share Alike 3.0 License< / a > < / p >
2022-02-17 22:33:27 -05:00
< / body >
< / html >
