xx is a Layer 1 blockchain that leverages its self-developed xx consensus to achieve linear scalability. xx consensus is based on Byzantine Fault Tolerant (BFT) consensus, which is characterized by low latencies, safety during large-scale node failure, and the ability to remain secure if up to one-third of the network is compromised or goes offline.
xx consensus leverages three core innovations:
- Committed Randomness is a way to generate unmanipulatable global randomness every block. Each node in the xx network publicly commits (using hash functions) to a large number of random values that they generate but keep secret. Every round, a node who is chosen to be a block producer (by a prior round’s random), reveals a predetermined secret that is verifiable by the rest of the network. When combined with the chain of all prior revealed randoms extending back to the random published in the genesis block, a new verifiable but unmanipulatable random is generated to schedule nodes for subsequent rounds.
- Endorser Sampling enables xx consensus to achieve its scaling properties by randomly selecting a constant-sized subset of the network to endorse a block. In BFT consensus protocols, communication latency becomes unworkable as the network grows in size, as all nodes must communicate with all other nodes. To compound the problem, a majority of nodes must receive and verify every transaction, which becomes infeasible when dealing with large, quantum-secure signatures in a large network. By sampling a subset of the network to receive, verify, and endorse the transactions in a block, the majority of nodes only need to receive a condensed ledger of all transactions along with the endorsement of the sampled nodes.
- Compact Group Endorsement Signatures can not only improve consensus performance but also allow for mobile devices to efficiently receive and verify proof that a transaction is complete. The xx network has developed a new quantum-secure group-signature scheme based on hash signatures that vastly reduces the size of proofs of finality. To achieve this, each endorser signs only a small number of bits corresponding to the block. As a result, each individual signature is insecure on its own, but if enough endorsers sign the same block, then the signature as a whole is quantum-secure, compact, and quick to validate.
$XX is the native digital currency of the xx network. $XX secures the network through staking, enables payments, incentivizes governance, and acts as the network’s economic vehicle.