Smart contract failures can cost millions of dollars and can even lead to death of companies and of cryptocurrencies. Moreover, smart contracts are easier to attack by hackers than ordinary software, simply because they are public on the blockchain and anyone can invoke them from anywhere. Therefore, there is an unprecedented need to guarantee the correctness of code.
It is well-known that the only way to guarantee code correctness is through the use of rigorous formal methods, where the correctness of the smart contract is expressed mathematically as a formal property, the programming language or virtual machine is also expressed mathematically as a formal model, and the former is rigorously proved from the latter. Moreover, the correctness of smart contracts must be independently checkable, without having to trust their authors or any auditing authorities. Therefore, they must be provided with machine checkable correctness certificates.
Yet another smart contract bug
Recently, a hidden DoS bug (called Gridlock) was revealed in Edgeware's Lockdrop smart contract that has locked hundreds of millions of dollars worth of Ether. Because of this bug, Edgeware had to newly deploy the fixed version of the contract, and as a result, two Lockdrop contracts (old version and new version) currently live in parallel on mainnet. (This means that you can send a transaction to either of these contracts to lock your Ether, until the old one is attacked and becomes incapable.)
In this article, we will review the Gridlock bug and discuss how formal verification can help to prevent this type of bugs.
Musab A. Alturki, Brandon Moore, Karl Palmskog and Lucas Pena
Earlier this year, Runtime Verification was engaged by Algorand to verify its consensus protocol. We are happy to report that the first part of the effort, namely modeling the protocol and proving its safety theorem, has been successfully completed. Specifically, we have used a proof assistant (Coq) to systematically identify assumptions under which the protocol is mathematically guaranteed to not fork.
Ethereum 2.0 is coming. And rest assured, it will be formally specified and verified!
Ethereum 2.0 is a new sharded PoS protocol that, at its early stage (called Phase 0), lives in parallel with the existing PoW chain (called Eth1 chain). While the Eth1 chain is powered by miners, the new PoS chain (called Beacon chain) will be driven by validators.
In February of this year Runtime Verification, Inc, (RV) received the very first security grant from the Ethereum Foundation to formally model/specify and verify the Casper smart contract.