Kaspa Identity Layer
This page describes a roadmap design for using the Kaspa BlockDAG as a decentralized identity layer. The current SecureChat release does not anchor keys, discover contacts or register relays on Kaspa.
Why Kaspa
BlockDAG Advantages
Kaspa's BlockDAG architecture provides the ideal properties for a decentralized identity system: fast finality, low cost, and battle-tested Proof-of-Work security without requiring stake or validators.
- 10 blocks per second — fast enough for real-time identity operations and key rotation
- Proof-of-Work security — same trust model as Bitcoin, no stake requirements or validator sets
- Minimal fees — identity anchor transaction costs fractions of a cent
- No smart contracts needed — simple UTXO transactions with OP_RETURN suffice
- Community operated — no single company controls the network
- GHOSTDAG protocol — parallel blocks mean no orphans, no wasted work
Identity Anchoring
X25519 Public Key in OP_RETURN
The proposed design would embed an X25519 public key in a Kaspa transaction's OP_RETURN field. This is not performed by the current app.
- One-time anchor: Public key is written to the chain once during setup
- OP_RETURN payload: X25519 public key (32 bytes) + Ed25519 signature
- Kaspa address = identity: Your Kaspa address becomes your SecureChat ID
- Key rotation: New anchor transaction with previous key's signature as proof
- No message content: Only identity data touches the chain — never message content
Contact Discovery
Find Contacts by Kaspa Address
In the proposed design, a future client would query the BlockDAG for a public-key anchor and verify its Ed25519 signature. Current contact exchange uses signed QR/text bundles instead.
- Lookup: Query Kaspa BlockDAG for OP_RETURN transactions from the target address
- Verification: Ed25519 signature proves the key was published by the address owner
- No phone numbers: No SIM card, no email, no centralized directory
- QR codes: Share Kaspa address via QR for in-person contact exchange
- Offline-capable: Once keys are cached locally, no network needed for verification
Relay Node Registry
Decentralized Relay Discovery
The roadmap proposes on-chain relay registration and discovery. Current online messages use the configured central signaling service.
- Registration: Relay operators publish endpoint + public key via OP_RETURN
- Permissionless: Anyone can register a relay node — no approval needed
- Liveness: Periodic heartbeat transactions prove the relay is still operational
- Client selection: Users choose relays based on latency, reputation, and geographic proximity
- Decentralized: No single entity controls which relays are available
KAS Micropayments for Relay Operators
Sustainable Relay Network
KAS micropayments are a research proposal for future relay incentives. No such payment or relay-market flow exists in the current client.
- Per-message payments: Tiny KAS amounts per forwarded message (fractions of a cent)
- Direct payment: Sender pays relay directly via Kaspa transaction
- No middleman: Payments go directly to the relay operator's Kaspa address
- Market pricing: Relay operators set their own rates — competition keeps prices low
- Privacy preserved: Payment does not reveal message content or recipient identity
Implementation Status
Roadmap — after core APK release
The Kaspa identity layer remains a roadmap layer after the core Android APK release. The cryptographic primitives (X25519, Ed25519) are already implemented in the SecureChat crypto stack via lazysodium-android. The on-chain integration, relay registry, and micropayment system are scheduled as post-v1 expansion work.
- Completed: X25519 + Ed25519 key generation and management
- In design: OP_RETURN transaction format and parsing
- In design: Relay node registry protocol
- In design: KAS micropayment flow and fee structure
- Planned: Kaspa testnet integration and end-to-end testing