☘️NOEL

Szabo’s Quorum Theory and the Only Real Computational Implementation 1/12 Nick Szabo @NickSzabo4 is known for Bit Gold and Smart Contracts, but he also wrote something foundational that most people overlooked: Quorums for deterministic computation. Not voting. Not committees. Actual replicated execution that must produce identical results. This idea would take more than a decade to materialize. --- 2/12 In Szabo’s definition, a quorum is not a set of validators raising their hands. It is a group of independent machines that must: • receive the same inputs • execute the same program • produce the same outputs bit-for-bit. If even one diverges, the system detects the fault. This is deterministic truth, not probabilistic agreement. --- 3/12 Szabo separated two categories: • Proof of Work for unforgeable costliness and Sybil resistance • Quorum computation for correctness of state transitions The ideal system would combine both. One to decide who may participate. One to decide what is true. --- 4/12 Many chains claim to use “quorums”: Ripple, Stellar, Cosmos, Algorand. But these are BFT messaging quorums, not computational quorums. They vote on blocks or messages. They do not independently compute results to achieve consensus. This distinction is essential. --- 5/12 How BFT chains work: Validator A proposes a block. Validators B, C, D vote to accept it. Consensus is reached on the container (the block). Execution happens afterward. They agree on the package, not the calculation inside. This is consensus on messaging. --- 6/12 Qubic works differently. There is no block producer and no proposal. All Computors execute the same instructions during the same tick. They submit their output hashes. A quorum is reached only if enough of them produce the exact same result. This is consensus on execution. --- 7/12 Before going further, one thing must be clear: Qubic does not use blocks. It uses ticks. A tick is a synchronized compute step. All Computors execute the same logic at the same moment and submit outputs. It functions like the clock cycle of a distributed CPU. Ticks advance computation, not storage. --- 8/12 Why does this matter? Because deterministic computation is the foundation for: • verifiable AI workloads • scientific compute • complex simulations • provable correctness of logic • parallel execution across hundreds of nodes You cannot achieve this with probabilistic block voting. --- 9/12 So why did no blockchain implement Szabo’s computational quorum? Because it requires: • deterministic execution • deterministic memory • identical CPU instruction flow • synchronized timing • a controlled environment • removal of OS-level nondeterminism Most blockchain architectures cannot meet these requirements. --- 10/12 This is where Sergey Ivancheglo (CfB) @c___f___b enters the story. The creator of NXT (first PoS) and IOTA (first DAG) spent more than a decade refining a system built on Szabo’s theory. He removed nondeterministic layers, built a deterministic compute engine, and implemented quorum-validated execution at scale. Szabo wrote the theory. CfB built the machine. --- 11/12 Qubic uses: • useful PoW for identity and ranking • quorum computation for truth • synchronized ticks for timing • deterministic native execution • parallel compute for ANN workloads and more It is the first real system where the consensus mechanism is the computation itself. --- 12/12 Most chains secure the ledger. Qubic secures the result of computation. No blocks. No fork choice. No leader races. Just replicated execution and a quorum validating the truth. Szabo theorized it. CfB implemented it. Qubic is where that theory runs. #Quorum #Qubic $Qubic qubic.org nakamotoinstitute.org/librar…