Proof of Personhood

The InterLink Chain introduces Proof of Personhood (PoP), a groundbreaking consensus mechanism that secures the network by ensuring only verified human users can participate as validators. Unlike traditional models such as Proof of Work, which relies on computational power, or Proof of Stake, which depends on token ownership, PoP ties validation directly to real human identities through the InterLink ID—a decentralized identity system anchored in unique biometric data. By requiring validators to hold a verified InterLink ID, PoP effectively prevents Sybil attacks, where malicious actors attempt to dominate the network with multiple fake identities. This human-centric design not only enhances security but also aligns with InterLink’s mission to create a trustworthy, inclusive, and decentralized ecosystem.

At the heart of PoP lies the InterLink ID, which revolutionizes biometric authentication by eliminating the need for centralized storage of raw biometric data, a common vulnerability in traditional systems. Instead, it leverages zero-knowledge proofs (ZKP) and homomorphic encryption to transform biometric inputs—such as facial images or fingerprints—into encrypted, irreversible representations. This ensures that each user’s identity is unique while safeguarding privacy, as no sensitive data is stored or exposed. The process begins in the Enrollment Phase, where a biometric input $B$ is converted into a feature vector $F = f(B) \in \mathbb{R}^d$ using advanced deep learning models like ResNet or Vision Transformers. To protect privacy, $F$ undergoes secure transformations, including random projection $F' = T F$ and Locality-Sensitive Hashing (LSH) to produce a binary hash $H(F') = (h_1, h_2, \ldots, h_m)$, where $h_i = \text{sign}(w_i^T F' + b_i)$. This hash is then encrypted using a Pedersen commitment $C = g^{H(F')} h^r \mod p$, which is stored in the Decentralized InterLink ZK Biometric Node Pool, ensuring decentralized and secure storage.

Privacy-Preserving Biometric Encryption

During the Authentication Phase, a user submits a new biometric input $B_{\text{auth}}$, which is processed into $F'_{\text{auth}}$. The user generates a zero-knowledge proof to demonstrate that $H(F'_{\text{auth}})$ matches the stored commitment $C$ without revealing the hash itself. The decentralized node pool collectively verifies this proof, ensuring secure and private authentication. AI enhancements, such as self-supervised learning (e.g., SimCLR), differential privacy, and GANs, further strengthen the system’s resilience against attacks and spoofing attempts.

PoP offers critical advantages in security, privacy, and compliance. Its multi-step encryption ensures irreversibility, while cancelability allows re-enrollment with a new transformation matrix if needed. Decentralization eliminates single points of failure, and the system aligns with regulations like GDPR and CCPA by minimizing data exposure and using ZKPs for verification. These features make PoP ideal for applications in finance, healthcare, and government services. Moreover, InterLink ID’s modular design—combining ZKPs with AI-driven biometrics—ensures adaptability to future threats, such as quantum computing, positioning it as a forward-thinking solution for digital identity verification.