Comment by vertex-four | Hacker News Reader

Comment by vertex-four | Hacker News Reader

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> However, a malicious node in the network can't present you with outdated information or false information, as the IPNS record is signed with the key from the peer.

False information - no. Outdated information - why not? What you've described in this comment doesn't solve it. If I signed that the name N points at hash H1 yesterday, and then signed that the name N points at hash H2 today, why can a malicious node not simply keep telling people asking for N that it points at H1?

Do IPNS signatures expire in a similar way to DNSSEC signatures? (Some poking around github says "maybe".) If so, does the owner of the IPNS name have to regularly connect to the network to refresh them? This would suggest that IPNS records can very easily disappear with no way to reinstate them, even if other nodes are keeping the data they point to up. Is this documented somewhere? Can I set a much shorter expiration time (e.g. 5 minutes for quickly-updating information)?

IPNS records have an optional and user-configurable expiry time, but more importantly, they contain a sequence counter.

So unless an attacker can completely disconnect you from everybody else who's interested in a particular IPNS address (and in that case you're lost anyway), they can't hoodwink you into going back to an old version.

I see. So if they can disconnect you from everybody else (for example, if they control the internet connection you're connected to), you have no way of telling whether they're replaying IPNS records to you.

The traditional internet solves the problem of not being able to trust your internet connection (say, in a coffee shop) with public key infrastructure so that the most a rogue internet provider can do is DoS you (they can't get a certificate for google.com and TLS is protected against replay attacks), so this sounds like a downgrade in actual security.

I think it's a bit unfair to pretend that TLS replay would be the same as having a not entirely updated IPNS record. The threat models are very different.

The corresponding attack against IPNS would be if the attacker could make your perspective of the world go backwards, and that is prevented by the sequence number.

Indeed, but TLS doesn't have the problem of replay at all (we hope), so IPNS is by design susceptible to a threat that the traditional internet is not in the case that your connection is untrusted.

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