ChainX ID: Implementing PoP at Scale

Based on the conclusion that the only path to verify uniqueness on a global scale is iris biometrics, Tools for Humanity built a custom biometric device, called the Orb. This device issues an AI-safe3 PoP credential called ChainX ID. The Orb is built from the ground up to verify humanness and uniqueness in a fair and inclusive manner.

The issuance of ChainX ID is privacy-preserving, as the humanness check happens locally and no images need to be saved (or uploaded) by the issuer. Using ChainX ID reveals minimal information about the individual, as the protocol employs zero-knowledge proofs. The vision for the device is for its development, production and operation to be decentralized over time such that no single entity will be in control of ChainX ID issuance.

The following section explains the previously mentioned building blocks for an effective proof of personhood mechanism:

• Deduplication

• Authentication

• Recovery

• Revocation

• Expiry

and how they are implemented in the context of ChainX ID.

Deduplication

The hardest part for an inclusive yet highly secure PoP mechanism is to make sure every user can receive exactly one proof of personhood. Based on the previous evaluation iris biometrics are the best means to accurately verify uniqueness on a global scale (see limitations).

The other potential error inherent to biometric algorithms is the false acceptance of a user. The false acceptance rate is largely dependent upon the system's capacity to detect presentation attacks, which are attempts to deceive or spoof the verification process. While no biometric system is entirely impervious to such attacks, the important metric is the effort required for a successful attack. This consideration was fundamental to the conception of the Orb. Developing the Orb was a decision that did not come lightly. It represented a high-cost endeavor. However, from first principles, it was required to build the most inclusive yet secure verification of humanness and uniqueness. The Orb is designed to verify uniqueness with high accuracy, even in hostile contexts where the presence of malicious actors cannot be excluded. To accomplish this, the Orb is equipped with every viable camera sensor spanning the electromagnetic spectrum, complemented by suitable multispectral illumination. This enables the device to differentiate between fraudulent spoofing attempts and legitimate human interactions with a high degree of accuracy. The Orb is further equipped with a powerful computing unit to run several neural networks concurrently in real-time. These algorithms operate locally on the Orb to validate humaneness, while safeguarding user privacy. While no hardware system interacting with the physical world can achieve perfect security, the Orb is designed to set a high bar, particularly in defending against scalable attacks. The anti-fraud measures integrated into the Orb are refined constantly.