"within 10 seconds of real time, but security is paramount" You cut off the important bit. Roughtime servers sign their responses, so you can be sure you aren'

"within 10 seconds of real time, but security is paramount" You cut off the important bit. Roughtime servers sign their responses, so you can be sure you aren't getting a malicious time response (or if you do, you can penalize that server). Per google [0]: "With only two servers, the client can end up with proof that something is wrong, but no idea what the correct time is. But with half a dozen or more independent servers, the client will end up with chain of proof of any server's misbehaviour, signed by several others, and (presumably) enough accurate replies to establish what the correct time is." [0] https://roughtime.googlesource.com/roughtime https://roughtime.googlesource.com/roughtime