# Plasma EVM change logs

#### [1.0](https://hackmd.io/s/SkoSGtXOm)
First version of Plasma EVM. It can't prevent block withholding attack.

#### [2.0](https://hackmd.io/s/BkHtXjSQ4)
[User-activated Fork](https://hackmd.io/s/ByeGtM5D7) enables users to make a fork if they notices the block withholding attack. It requires significant finantial and time cost. User can safely exit their assets and states by forking the chain.

#### [2.1](https://hackmd.io/s/HyZ2ms8EX)
- [User-activated Fork](https://hackmd.io/s/ByeGtM5D7) paper is fully merged into this paper
- Various cases in submitting URB is added
- Challenge case for URB is added
- Minimum point of cost functions for URB, ERU is modified
- Issues related with UAF model are added