Motivation

Every 2 weeks or so, we see a fork in the bitcoin network. A good way to spot them is through RSS feed provided by Forkmonitor[here] or run a bunch of full nodes yourself.

For the same reason, protocols like Rootstock make you wait for 100 bitcoin blocks before confirming deposit to account for forks in the network. The only other alternative available is to trust a centralized server that can confirm deposit after six block or so.

Since there are no light clients available in Bitcoin, we wanted to a way to have predictive finality on transaction, such that whenever there is a fork in the bitcoin network, the chain should know it.

Validity gadget is a construction based on Joachim Neu's and Ertem Nusrat Tas work at Stanford[link1][link2].