In addition to the original version of sidechains that was originally announced back in April 2014 by Blockstream’s Adam Back and Austin Hill, there are also a few other, unique ways to enable a two-way peg between Bitcoin and another blockchain.
“There are several ways to implement a two-way peg,” Lerner told Epicenter Bitcoin. “One is the sidechain concept that was developed by Blockstream, and the other is the drivechain concept that was developed by [Bloq Economist] Paul Sztorc. The third one is basically have a set of notaries that have custody of the funds that are transferred to the Rootstock platform.”
Rootstock has created a hybrid system that combines all three of the mechanisms for a two-way peg mentioned by Lerner. “On the Rootstock side, we have a sidechain; on the Bitcoin side, we have a mixture of federation and a drivechain, which allows miners and a set of renowned parties to have custody of the bitcoins that are transferred to the Rootstock platform.”
Lerner is the author of a Bitcoin improvement proposal (BIP) that would add a new opcode to enable drivechain capabilities.
http://coinjournal.net/rootstock-spin-bitcoin-sidechains/
