Proof-of-Proof (PoP)
"Proof-of-Proof is a novel consensus protocol invented by VeriBlock, Inc. which allows any blockchain (including sidechains and permissioned ledgers) to inherit the full security of Bitcoin in a truly decentralized, trustless, transparent, and permissionless (DTTP) manner. It does so by gamifying the publication of data representing a blockchain's present state to Bitcoin (directly or indirectly) such that any user can participate and receive compensation for enabling blockchains to inherit Bitcoin's security."
"Every time a new blockchain joins the VeriBlock ecosystem or an existing one increases in value, all other blockchains in the VeriBlock ecosystem benefit by enjoying the additional security and decentralization that results from VeriBlock's increased network effect."