consensusmechanismen

Consensusmechanismen are protocols used by distributed systems to achieve agreement on a single history of transactions or state in the presence of unreliable or potentially malicious participants. They enable coordination without a central authority and are designed to ensure safety (the system does not adopt conflicting histories) and liveness (the system continues to process new transactions).

Common families and approaches include:

- Nakamoto consensus, typically based on proof of work, where participants compete to add blocks to a chain. Security relies on the assumption that the majority of economic power controls the honest chain. Finality is probabilistic; the likelihood of reversal decreases as more blocks are added, but no absolute finality is guaranteed at a fixed moment.

- Proof of stake and its variants, where validators are chosen according to their stake or influence in the system. These mechanisms aim to be more energy-efficient and can offer faster or stronger finality in some designs, with penalties (slashing) for misbehavior.

- Byzantine fault-tolerant (BFT) protocols, such as PBFT and its successors, which provide fast, deterministic finality for permissioned or relatively small networks. They tolerate a fixed fraction of faulty nodes but typically require explicit trust relationships or known participants.

- Delegated proof of stake, proof of authority, and other hybrids, which balance governance, scalability, and security by decentralizing or centralizing validator selection.

Key considerations include network permissioning (permissioned vs permissionless), energy consumption, latency, throughput, finality guarantees, and resistance to attacks (e.g., 51% or long-range attacks). In practice, many systems mix elements to align security, performance, and governance with their use case.