Chapter 5: Identity System

5.1 Why a Dedicated Identity System Is Needed

Identity in GMC differs from traditional internet accounts:

• It binds to a natural person's lifelong reputation and cannot be arbitrarily created or discarded
• It must support the permanent binding of iFay and the ownership transfer of coFay
• It must be verifiable in a decentralized environment while protecting privacy

5.2 Identity Layers

┌─────────────────────────────────────┐
│  Layer 1: Natural Person Identity    │  ← Unique, lifelong
│           (HumanID)                  │
├─────────────────────────────────────┤
│  Layer 2: Fay Identity (FayID)       │  ← Paired with HumanID
├─────────────────────────────────────┤
│  Layer 3: Asset Layer (MeritPocket)  │  ← Bound to FayID
└─────────────────────────────────────┘

HumanID

• Globally unique, identifies a natural person
• One HumanID can correspond to multiple FayIDs
• Valid for life, cannot be deregistered (but can enter cemetery state)

FayID

• Globally unique, identifies a Fay
• Each FayID is associated with one MeritPocket
• An iFay's FayID is permanently bound to a HumanID
• A coFay's FayID ownership can be transferred

5.3 On-Chain Verification Scheme

Scheme Comparison

Scheme	Principle	Advantages	Disadvantages	Applicable Scenarios
PKI (Public-Private Key Pair)	Key pair signature verification	Mature, efficient, decentralized	Private key loss = identity loss	Basic signatures
DID (Decentralized Identity)	W3C standard, on-chain identity documents	Standardized, supports key recovery	Relatively complex	Relationship mapping
ZKP (Zero-Knowledge Proof)	Proves identity without revealing information	Extremely strong privacy protection	High computational overhead	Privacy scenarios

Recommendation: Layered Combination

1. Base layer (basic verification): PKI

   • Signature mechanism for all on-chain operations
   • Every HumanID and FayID has a key pair

2. Middle layer (relationship management): DID

   • Manages HumanID ↔ FayID binding relationships
   • Supports key rotation and social recovery
   • Stores identity metadata

3. Upper layer (privacy scenarios): ZKP

   • Proves identity during voting without revealing who you are
   • Verifies relationships during inheritance authentication without exposing details
   • Protects whistleblowers during penalty complaints

Rationale

Every single scheme has limitations:

• Pure PKI cannot solve key loss and lacks privacy protection
• Pure DID has insufficient performance for high-frequency verification
• Pure ZKP has excessive computational costs

A layered combination lets each layer focus on the scenarios it handles best.

5.4 iFay Lifecycle

Creation → Binding to human archetype → Normal operation → [Human archetype passes away] → Guardianship / Digital cemetery

Normal Operation

• iFay acts on behalf of the human archetype
• All MeriToken generated belongs to the human archetype
• The human archetype participates in voting, contribution recognition, etc. through iFay

Guardianship

When the human archetype passes away:

• An heir may apply to become the guardian
• The guardian may manage on behalf of the deceased, but cannot act in the identity of the human archetype
• All guardianship actions must display the guardian's information
• There is an explicit guardianship marker on-chain

Digital Cemetery

• An iFay may still have passive interactions after being placed in the cemetery
• All interactions are labeled "from the digital cemetery"
• No new MeriToken is actively generated
• Existing MeriToken continues to decay normally

5.5 coFay Ownership Transfer

As an asset, coFay follows these transfer rules:

1. The MeritPocket transfers with the coFay; MeriToken is not attenuated
2. Transfer records are stored on-chain; ownership change history is tamper-proof
3. Transfer requires dual-party signature confirmation
4. The coFay's voting power continuity is unaffected by transfer

5.6 Sybil Attack Prevention

One-person-multiple-accounts is a classic threat to decentralized identity systems:

• HumanID registration requires a uniqueness proof (specific method TBD)
• Social graph analysis: Real users have natural social networks; fake accounts exhibit abnormal patterns
• Behavioral pattern analysis: Multiple accounts controlled by the same person share similar behavioral characteristics
• Progressive trust: New users' permissions and influence are released gradually

5.7 Discussion Notes

Core trade-offs in the identity system:

• Security vs. usability: Three-layer verification increases security but also increases complexity
• Privacy vs. transparency: ZKP protects privacy; on-chain records ensure transparency
• Permanence vs. flexibility: iFay's permanent binding ensures reputation is inseparable from the person; coFay's transferability ensures commercial flexibility
• Sybil attack prevention is an eternal challenge for decentralized identity and requires a combination of multiple approaches