Hi, I'm playing around with the different timers of DNSSEC. Usually these timers are a balance between a low overhead vs quick propagation: * A high TTL gives more caching and thus less load on the authoritative server; but it takes a long time for updates to propagate. * A short RRSIG lifetime limits the amount of time old answers can be replayed; but requires regular resigning
Or they are a balance between low overhead and security: * A DNSKEY (ZSK or KSK) used for a long time risks being cracked; changing it often requires maintenance. But for the NSEC3 salt, I can't really figure out what the components are... If someone is brute-forcing the NSEC3 hashes (cfr Daniel Bernstein's presentation), changing the salt requires only a minuscule change on their end. I see no reason to change the NSEC3 salt at all. So the question is: what is a normal lifetime of an NSEC3 salt, and for what reason? And while I'm at it: what lifetimes, keylengths and algo's are popular for ZSK's and KSK's? Are your keys stored online or offline? I'm thinking of using ZSK's of 1280bits for a year (since I'm lazy) and KSK's of 2048bits until I feel like changing it (i.e. pretty much indefinitely). This would allow the KSK to be offline, and only needed once a year. I'd like to use NSEC3 with RSA/SHA-512, but that might be unreasonable strong compared to my lazy lifetimes. On the other hand, RSA/SHA1 is more compatible (eg with bind 9.6). My signature lifetime will probably be 3 weeks, resigning every week. With 1 week expire timers, it leaves 1 week of margin to correct errors. Are these values/argo's sane? Thx, Niobos PS: don't try talking me into using NSEC. I'm using NSEC3 "because I can", not that it would be any problem at all if they walked my zone. _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users