Phillip Hallam-Baker <hallam@xxxxxxxxx> wrote: > > 2. The current time is a matter of convention rather than a natural > property. It is therefore impossible to determine the time without > reference to at least one trusted party. Preferably more than one so you can use quorum agreement and minimize the amount of trust you put in any single time reference. > 4) In the case of DNSSEC the window of vulnerability is actually fairly > small since rewinding the time to a date in the past only helps an attacker > if they had compromised the system on that date. So if you rely on RRSIG timestamps or SOA serial numbers to get the time, an attacker that manages to compromise DNSSEC can replay that compromise indefinitely. > The real design decision is who you decide you are going to rely on for > (3). TLS is proof against replay attack due to the exchange of nonces. Right. Tony. -- f.anthony.n.finch <dot@xxxxxxxx> http://dotat.at/ Forties, Cromarty: East, veering southeast, 4 or 5, occasionally 6 at first. Rough, becoming slight or moderate. Showers, rain at first. Moderate or good, occasionally poor at first.