Cardano

Cardano utilizes a peer-reviewed Ouroboros Proof-of-Stake (PoS) consensus mechanism, where validators stake ADA to secure the network, with rewards distributed every five days in epochs and slashing for misconduct like downtime, enabling predictable transaction costs through its extended UTXO (eUTXO) model while separating settlement and computation layers for enhanced security and scalability.

However, the validator set of approximately 2,145 active stake pools shows moderate diversity, with geographic spread across over 100 countries but effective control concentrated among top operators (~30-40% of staked ADA) and reliance on cloud services creating chokepoints, as the Nakamoto Coefficient stands at 22, meaning 22 entities could control 33% of the stake, raising potential collusion risks despite pool saturation caps and permissionless participation, leading to a lower Decentralization score.

Security is high, supported by ~$8.8 billion in economic security through ~21.55 billion staked ADA, with no successful 51% attacks or consensus-layer exploits in history from 2017-2025, though rare incidents like the January 2023 node outage (brief 50% offline), June 2024 DDoS (mitigated without halt), and November 2025 chain split (14-hour bifurcation from a bug, resolved without losses) highlight occasional disruptions patched quickly without user impact.

Speed is very poor, with average block times of ~20-22 seconds and real-world throughput of ~0.74-2 TPS (maximum recorded ~11.62 TPS), achieving probabilistic finality in ~1-2 minutes, lagging under load in 2025 with clunky DeFi UX.

Immutability is high, with no state reversals, rollbacks, or clawbacks in history, but hard forks approximately once per year (e.g., Chang in 2024, Plomin and Ouroboros Phalanx in 2025) driven by community-voted CIPs since Voltaire era, plus brief halts in incidents like 2025's chain split without state changes, demonstrating flexibility via hard fork combinators while lacking admin keys for routine interventions.

Censorship Resistance is high as the protocol lacks blacklists or freezes, with no documented incidents of transaction blocking or OFAC-compliant pools in 2025 or history, minimal MEV due to eUTXO reducing steering incentives, and Ouroboros randomization preventing exclusion although stake concentration poses minor theoretical collusion risks under regulatory pressures.

Ownership Distribution is broad, with no premine beyond the 2015-2017 ICO which distributed to ~72,000 participants. Over 4.83 million unique wallets, with the top 10 holders control ~9.99% (largely custodial) and the top 100 hold ~29.6%.