Teechain: Reducing Storage Costs on the Blockchain With Offline Payment Channels

Blockchain protocols such as Bitcoin [4] exchange payments in a secure and decentralized manner, but their performance is limited due to their need to achieve consensus across a network [1], and each node in the network needs to process the entire blockchain, which introduces major storage limitations. Cryptographic payment channels [2, 5] have been proposed as a second tier on top of the blockchain, allowing efficient direct payments between parties, and the removal of many payments from the blockchain to only the participating parties of the channel. Existing payment channel protocols, however, have two limitations: (i) their security relies on synchronous access to the underlying blockchain, which an attacker may prevent; and (ii) they suffer from long channel establishment times when placing collateral deposits on the blockchain.