• DOI:10.1145/3341301.3359627
• Corpus ID: 202540005

Teechain: a secure payment network with asynchronous blockchain access

@article{Lind2019TeechainAS,
  title={Teechain: a secure payment network with asynchronous blockchain access},
  author={Joshua Lind and Oded Naor and Ittay Eyal and Florian Kelbert and Emin G{\"u}n Sirer and Peter R. Pietzuch},
  journal={Proceedings of the 27th ACM Symposium on Operating Systems Principles},
  year={2019}
}

• Joshua Lind, O. Naor, +3 authors P. Pietzuch
• Published 18 July 2017
• Computer Science, Mathematics
• Proceedings of the 27th ACM Symposium on Operating Systems Principles

Blockchains such as Bitcoin and Ethereum execute payment transactions securely, but their performance is limited by the need for global consensus. Payment networks overcome this limitation through off-chain transactions. Instead of writing to the blockchain for each transaction, they only settle the final payment balances with the underlying blockchain. When executing off-chain transactions in current payment networks, parties must access the blockchain within bounded time to detect misbehaving parties that deviate from the protocol. This opens a window for attacks in which a malicious party can steal funds by deliberately delaying other parties' blockchain access and prevents parties from using payment networks when disconnected from the blockchain. We present Teechain, the first layer-two payment network that executes off-chain transactions asynchronously with respect to the underlying blockchain. To prevent parties from misbehaving, Teechain uses treasuries, protected by hardware trusted execution environments (TEEs), to establish off-chain payment channels between parties. Treasuries maintain collateral funds and can exchange transactions efficiently and securely, without interacting with the underlying blockchain. To mitigate against treasury failures and to avoid having to trust all TEEs, Teechain replicates the state of treasuries using committee chains, a new variant of chain replication with threshold secret sharing. Teechain achieves at least a 33X higher transaction throughput than the state-of-the-art Lightning payment network. A 30-machine Teechain deployment can handle over 1 million Bitcoin transactions per second.