Re: One real life secure random generator

Ben Laurie (ben@algroup.co.uk)
Sun, 12 Jul 1998 11:39:04 +0100

• Next message: Peter Gutmann: "cryptlib public beta released"
• Previous message: Bill Frantz: "Re: What is entropy?"
• In reply to: Mike Rosing: "What is entropy?"
• Next in thread: Bill Stewart: "Re: Random Data from Geiger Counter"

Bill Frantz wrote:
> (1) UI events, mouse and keyboard. Every UI event is hashed into the pool.
> If the mouse has moved on at least one axis since the last event, we score
> 1 bit of entropy (no motion scores zero bits). If the key pressed is
> different that the last 4 key presses, we score 1 bit of entropy. During
> the startup phase, we continuously monitor mouse position. After we have
> 160 bits, we only measure mouse position on mouse down and mouse up events.

I'd say this was risky. Mouse down/up events happen in far fewer places
than general mouse movement, at least on my machine: they mostly are
menu selections, from windows that stay in the same place for a very
long time (weeks). Sampling at regular intervals would seem safer.

Cheers,

Ben.

-- 
Ben Laurie            |Phone: +44 (181) 735 0686| Apache Group member
Freelance Consultant  |Fax:   +44 (181) 735 0689|http://www.apache.org/
and Technical Director|Email: ben@algroup.co.uk |
A.L. Digital Ltd,     |Apache-SSL author     http://www.apache-ssl.org/
London, England.      |"Apache: TDG" http://www.ora.com/catalog/apache/
WE'RE RECRUITING! http://www.aldigital.co.uk/recruit/

• Next message: Peter Gutmann: "cryptlib public beta released"
• Previous message: Bill Frantz: "Re: What is entropy?"
• In reply to: Mike Rosing: "What is entropy?"
• Next in thread: Bill Stewart: "Re: Random Data from Geiger Counter"