The core security proposition of Plasma revolves around honest users being able to exit the child chain (in other words, withdraw funds to the root chain) at any time. To exit the child chain, a user submits an exit transaction – along with an exit bond – to the root chain. The exit is subject to a “challenge period,” during which any user can prove, if applicable, that the exit is invalid. If successfully shown to be invalid, the exit is not processed, and the challenger is awarded the exit bond. This exit game is solely dependent on the root chain.

As the child chain relies on the root chain to be its ultimate arbiter, it must periodically commit a hashed version of its state changes to the root chain by way of a smart contract. As opposed to submitting individual transaction data onto the root chain, the child chain bundles transactions into a Merkle tree and submits the root hash. Beyond these core elements, there is no prescribed configuration for a Plasma chain. They can take on different consensus protocols, block validation mechanisms, or fraud proofs. The design is adaptable to the use case. OMG Network is based on the Plasma MoreVP design, an extension of Minimum Viable Plasma optimized for the settlement of payments and value exchange between users and exchanges.

The original OMG Network team (under the OmiseGO name) co-authored the original Plasma white paper with Joseph Poon and was also the first project to perform an airdrop, a way to more widely share ownership of our token with the existing Ethereum community.