KERI & Midnight — Conceptual Comparison
Summary
KERI solves programmatic identity and trust.
Midnight solves privacy-preserving computation and settlement.
They are complementary, not competitive.
Core Intent
| System | Primary Goal |
|---|---|
| KERI | Establish and prove entity continuity and authority without exposing identity data. |
| Midnight | Execute private business logic and verify zero-knowledge proofs on a blockchain network. |
What Each Actually Proves
| Question | KERI | Midnight |
|---|---|---|
| “Is this the same entity across time?” | ✅ via Key Event Log (KEL) | ❌ not its purpose |
| “Is this entity authorised to take action?” | ✅ via ACDC + trust registries | ⚠️ only if a proof is provided |
| “Can we minimise disclosure?” | ✅ rationale + selective fields | ✅ zero-knowledge proofs |
| “Can a smart contract enforce the rules?” | ➖ external to protocol | ✅ native to protocol |
Privacy Philosophy
| Area | KERI | Midnight |
|---|---|---|
| What becomes public | Key events (no PII) | Proof hashes + on-chain public elements |
| What stays private | PII, credential details, correlators | Raw values and internal data |
| Anti-correlation | Strong by design | Depends on circuit design |
| Privacy model | Minimum rationale | Minimum disclosure |
Placement in the Transaction Lifecycle
| Stage | Best Fit |
|---|---|
| Identify entity | KERI |
| Prove authority / membership | KERI + ACDC |
| Validate access / rights | KERI + trust registries |
| Execute logic privately | Midnight |
| Publish result / settlement | Cardano |
Developer Experience
| Dimension | KERI | Midnight |
|---|---|---|
| Deployment model | Offline / federated / distributed | Confidential smart-contract L2 |
| Required cryptography | Standard signatures | zk-SNARK / private proof systems |
| Integration cost | Low (JSON/HTTP, libs) | Higher (circuits, proof tooling) |
| Time-to-value | Fast for real-world identity | Longer, for privacy computation |
Practical Interpretation
- KERI handles who is acting and why they are authorised.
- Midnight handles whether the private business logic is correctly executed.
Identity and trust come first → KERI
Private permissioned execution comes later → Midnight
Analogy
KERI = passport + licence validation
Proves an entity and its authority without revealing personal details.
Midnight = confidential courtroom
Executes the rules privately based on zero-knowledge proofs.
Summary
KERI provides practical, programmatic identity and trust for today.
Midnight provides private logic execution when identity meets sensitive transactions.