Statechain design proposed without requiring Bitcoin consensus changes
Ruben Somsen described a statechain design for transferring control of Bitcoin UTXOs off-chain without requiring a Bitcoin consensus change.
In March 2020, Ruben Somsen proposed a statechain construction that would let ownership of a particular Bitcoin output be transferred repeatedly without putting every transfer on the blockchain. The design used cooperation with a statechain entity while attempting to prevent that entity from unilaterally stealing the coins.
The proposal was notable because it explored a new scaling and privacy direction without requiring a soft fork. At this stage it remained a design proposal rather than deployed Bitcoin infrastructure, but it helped define a family of off-chain custody and transfer ideas that would continue to be explored later.