Time synchronization issues

Adam Shostack adam at homeport.org
Tue Nov 4 23:38:43 UTC 2003

On Tue, Nov 04, 2003 at 12:47:17PM -0500, Joel N. Weber II wrote:
| So, if you're trying to design a system that's secure, the real issue
| to worry about is whether there are circumstances where an attacker
| can manipulate clocks to be able to use a certificate that's invalid.
| If you're really relying on the clocks being accurate, then you need
| to have documentation that says to people running onion routing
| software, ``don't configure your computer to use rdate -s
| trusted-time-server.example.com every time it boots, for any protocol
| such as rdate which is not cryptographically authenticated.''  (This

I mostly agree, but want to say if it's essential for the security of
the system, the software needs to verify it.  Nobody reads the


"It is seldom that liberty of any kind is lost all at once."

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