# Timewarp attack 600 second grace period

**URL:** <https://delvingbitcoin.org/t/timewarp-attack-600-second-grace-period/1326>\
**Category:** Protocol Design\
**Tags:** softfork\
**Created:** [December 17, 2024, 6:31am UTC](https://delvingbitcoin.org/t/timewarp-attack-600-second-grace-period/1326 "2024-12-17T06:31:46Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![sjors](https://delvingbitcoin.org/user_avatar/delvingbitcoin.org/sjors/32/59_2.png) [@sjors](https://delvingbitcoin.org/u/sjors)\
**Post date:** [December 17, 2024, 11:39am UTC](https://delvingbitcoin.org/t/timewarp-attack-600-second-grace-period/1326/3 "2024-12-17T11:39:44Z")

</div>

The original consensus cleanup proposal uses 600 seconds for the reasons I describe above.

The testnet4 implementation started out with 7200 seconds. This was to allow miners to use the system clock. But that was considered a bad idea and so it was reverted back to 600 here: [Move maximum timewarp attack threshold back to 600s from 7200s by TheBlueMatt · Pull Request #30647 · bitcoin/bitcoin · GitHub](https://github.com/bitcoin/bitcoin/pull/30647)

And so I’m proposing to bring it back to 7200, but not for the reason testnet4 initially did it.

As you say, anything less than 1 day is probably good enough.

Seperate from that is your observation here: [Zawy’s Alternating Timestamp Attack](https://delvingbitcoin.org/t/zawy-s-alternating-timestamp-attack/1062)

---

_[View the full topic](https://delvingbitcoin.org/t/timewarp-attack-600-second-grace-period/1326)._