Towards self-stabilizing blockchain, reconstructing totally erased blockchain

Blockchains are commonly used for crypto-currency systems, where they publicly store transactions. In a permissioned blockchain, only a few participants (nodes) can push new transactions to the chain. The known boundary on the number of faulty participants – up to f for 3f+1 participants – may be surpassed, causing the underlying consensus algorithm (BFT) to fail. When a malicious adversary compromises or corrupts enough nodes it may lead to the complete corruption of the ledger and even to the destruction of ledger copies the nodes hold. We suggest a reconstruction solution for the blockchain in the event of such an attack. We present a technique using verifiable secret sharing (VSS), making our solution immediate, requires no trust between the different blockchain parties, and provides each user an independent reconstruction. Our solution enables the exposure of an end-user's private key in case of dishonest reconstruction, thus, removing the incentive of such an act.