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30th DistSys Reading Group - NTP

Posted at — Jan 26, 2021

What better way to start a new year than with a paper discussing how to change time?

In the 30th session we discussed a paper which I think has much up its sleeves - Attacking the Network Time Protocol. First off the paper gives us a good introduction to the inner working of the network time protocol. Next up it examines the broader ecosystem as well as why we need accurate time in the first place. Once we established enough background, the paper dives into how one can attack the protocol, starting off with on-path attacks all the way to some crazy (creative) off-path attacks. Last but not least, the list of references at the end is a small treasure trove.

Malhotra, Aanchal, et al. “Attacking the Network Time Protocol.” NDSS. 2016.

https://eprint.iacr.org/2015/1020.pdf

You might have come across the work of one of the authors, Sharon Goldberg. In case you are looking for more material I can recommend the recording of Sharon’s talk “On the Security of the Network Time Protocol”.

Here are the notes I used during the session. You find numerous related references (various talks, bitcoin timing attack, NTS, PTP, Roughtime, …) in there.