Idena

Idena's core mechanism replaces energy-intensive mining with human identity verification. Participants prove they are unique humans by solving AI-hard CAPTCHAs simultaneously during a global ceremony called a validation ceremony. This creates a Sybil-resistant network where one person equals one validated identity, or 'Idena'. This consensus underpins the network's democratic governance and fair distribution of rewards.

The periodic event where all network participants (validators) must prove their humanity to maintain their status. Key aspects include:

• Synchronous Solving: All participants solve a series of flip tests (cryptographic CAPTCHAs) at the same appointed time.
• Flip Creation: Validators create these tests for others, earning rewards for high-quality flips.
• Ceremony Failure: Missing the ceremony or failing the tests results in a loss of validation status and mining rewards. This process ensures the network's ongoing resistance to bot infiltration.

A validated identity is a non-transferable cryptographic key representing a proven unique human. It has a status level (Newbie, Verified, Human) that determines mining rewards and voting power. Reputation is built through consistent participation in validation ceremonies and honest flip creation. This system enables one-person-one-vote governance for on-chain proposals and creates a foundation for applications requiring verified human users, such as universal basic income experiments or decentralized social networks.

Unlike Proof-of-Work, Idena mining is accessible and energy-efficient. Validated identities can mine the native iDNA token by simply keeping their node online. Rewards are distributed based on:

• Identity Status: Higher status levels (Human) earn more.
• Invitation Tree: Rewards are shared with those who invited you to the network.
• Flip Contributions: Creating high-quality flips for validation ceremonies provides additional income. This model incentivizes network growth and active participation in its security.

Idena implements a Decentralized Governance Organization (DGO) where every validated identity has a vote. Proposals for network upgrades, funding from the community treasury, or parameter changes are submitted and voted on-chain. Voting power is weighted by identity status, ensuring Sybil-resistant decision-making. This gives the community direct control over the protocol's development and resources without relying on centralized foundations or developers.

The network is built for resilience and accessibility:

• Client-Side Validation: The validation ceremony runs in a participant's browser, ensuring privacy and decentralization.
• Ethereum Virtual Machine (EVM) Compatibility: Supports smart contracts and interoperability with the Ethereum ecosystem.
• Lightweight Node: The node software is designed to run on consumer hardware, lowering the barrier to participation.
• Censorship Resistance: The decentralized and pseudonymous nature of identity verification makes the network difficult to censor or shut down.

The primary attack surface is the validation ceremony. An attacker could attempt:

• Pre-generated Flips: Submitting predictable or pre-solved image puzzles.
• Automated Solving: Using AI/computer vision to solve flips faster than humans.
• Collusion Networks: Coordinating multiple fake identities to pass validation.

Idena mitigates these by using user-generated, unique flip content, time-limited solving periods, and consensus-based scoring that flags suspicious patterns.

The invite tree is a critical security component. New identities require an invite from an existing, validated user, creating a web of trust. Attacks here include:

• Invite Selling: Monetizing invites to create fake identities.
• Deepfake Verification: Using generated media to bypass video verification.

Countermeasures include social graph analysis to detect invite-selling patterns, penalties for inviters whose invites fail, and mandatory video verification for certain validation tiers.

Unlike other chains, Idena's state (the validated identity set) is reset each epoch (approximately 2 weeks). This limits the impact of certain attacks but introduces a unique vector: epoch poisoning. An attacker could attempt to flood the network with low-quality or fraudulent identities during one epoch to disrupt the next. The protocol uses staking requirements and reputation scores to gate participation and filter out malicious actors between epochs.

Idena's human-centric validation introduces a trade-off. While highly Sybil-resistant, the requirement for synchronous global ceremonies and KYC-like video checks can be seen as a centralizing force and a potential censorship vector. The network's security relies on a geographically and culturally diverse set of validators to prevent regional biases or exclusion from dominating the validation process.

Standard blockchain attack vectors also apply:

• Private Key Management: Loss of the Idena key file means permanent loss of the identity and its stake.
• Client Vulnerabilities: Bugs in the Idena desktop client could be exploited.
• Network-Level Attacks: DDoS attacks targeting the specific timing of validation ceremonies. Security relies on robust client software, secure key storage practices, and a resilient peer-to-peer network.