Malicious node operator controlling (n - t) + 1 of the signers set can hold network to ransom

[ameba23]

Since entropy-tss is run in a TDX enclave, node operators are unable to read keyshares or modify the the behaviour of entropy-tss, which mitigates many possible attacks from malicious node operators.

However, they can stop the virtual machine process of the TDX guest from running. If they control more than n - t members of the current signer set, and stop all their nodes from running, it will be impossible for the network to sign messages or do a reshare. At this point the entropy network can only continue with cooperation from the node operator.

Of course they can be slashed for this, but it may be the case that their combined stake is sufficiently smaller than the network's total value to make a ransom attack worthwhile.

[mixmix]

is it possible to move knowledge of whether a node is an active signer to inside the enclave? I guess you could infer a lot from the network traffic still...

[ameba23]

Thats a really good idea which would help with a whole bunch of possible attacks. But it would mean deep changes to our current setup, and make public verification and slashing etc much more complicated. And yes, i think node operators could figure it out pretty easily from traffic analysis.