Subject: Re: PROPOSAL: adding capability for blowfish passwords
To: Steven M. Bellovin <email@example.com>
From: Michael Eriksson <Michael.Eriksson@era-t.ericsson.se>
Date: 06/07/2002 00:30:19
Steven M. Bellovin wrote:
> In message <firstname.lastname@example.org>, Tero Kivinen writes:
> >Actually I think the num_iterations should be stored along with the
> >salt to the encrypted password. This way the num_iterations can be
> >changed by changing the passwd.conf, and all new passwords would start
> >using the new num_iterations. Also the default could be something
> >num_iterations = time(NULL) / div + base;
> >so it goes up over time, as the cpu speeds go up too... Of course the
> >div and base could be parameterized in the /etc/passwd.conf too...
> Clearly, the number of iterations for a given password must be stored
> with the hashed password. My comment was about the number to be used
> at password change time. Your default is interesting -- I was about to
> object that time() returns the number of seconds since the epoch,
> rather than a measure of the machine's speed -- until I realized that
> that was exactly what you meant! Very clever...
You are forgetting that Moore's law is exponential, not linear...
Michael Eriksson <email@example.com>
/usr/sys/ken/slp.c: * You are not expected to understand this.