Why it's different
Confidential AI is a real field with serious products in it. Tinfoil, Phala's RedPill and Apple's Private Cloud Compute all prove something true: your request was processed privately. Epheia is built on the same foundation and answers the question that comes next.
What happened to your data afterward?
| Tinfoil | RedPill (Phala) | Apple PCC | Epheia | |
|---|---|---|---|---|
| AI runs inside confidential hardware | Yes | Yes | Yes | Yes |
| Hardware verified before your data is sent | Yes, open-source client check | Partial: via API and explorer | Yes, built into the OS | Yes, by your own browser, in the page |
| What you hold after the session ends Only Epheia | Nothing | A per-response signature | Nothing | A full-session receipt |
| Evidence your data was erased Only Epheia | No | No | No | Yes: attested crypto-erasure with a read-back self-test |
| Limit on what the system learns from you Only Epheia | Policy promise | Policy promise | Policy promise | A mathematical budget, recorded in the receipt |
| How an outsider checks it later Only Epheia | Live checking, not post-hoc | Verify the response signature | Not user-retrievable | Free public verifier, CLI or in-browser: 27 graded steps |
Row by row
A table that flatters us is worth nothing. Here is what each row does and does not claim.
- AI runs inside confidential hardware
- This is now table stakes, and that is genuinely good news. The hardware foundation is no longer exotic, which is what makes the next rows the interesting ones.
- Hardware verified before your data is sent
- Several vendors verify before sending. The difference is where the check runs and whether you can watch it happen. Epheia runs it in the page you are already looking at, and refuses to send if it fails.
- What you hold after the session ends
- This is the crux. Phala issues a per-response signature, which is a real artifact but scoped to one response. Epheia issues one artifact covering the whole session, including its end.
- Evidence your data was erased
- Apple Private Cloud Compute performs real cryptographic erasure, which makes it the closest prior art, but it issues no user-held receipt of that erasure. This row is about the evidence you can keep, not about who erases well.
- Limit on what the system learns from you
- Differential privacy itself is mature and widely used, so the novelty is not DP. It is that the epsilon and delta budget is committed inside a receipt a third party can re-check. On Epheia this learning is strictly opt-in and off by default.
- How an outsider checks it later
- Live checking answers "is it safe right now". A receipt answers "was it safe then", months later, to someone who was not present. Those are different questions and auditors ask the second one.
How we built this comparison
Assessments are as of July 2026, taken from each vendor's own public documentation rather than from testing their systems. Products move fast, and any of these rows could be out of date by the time you read it.
The comparison is deliberately narrow: it is about the artifact the user is left holding after a session, not the quality of anyone's enclaves. On the enclave axis these are all credible products, and we say so because it is true.
We also name our closest prior art rather than hiding it. Apple Private Cloud Compute does real cryptographic erasure without a user receipt. Phala issues a user-held, re-verifiable artifact that proves the genuine code ran rather than that data was erased. Epheia's claim is the combination of the two, not the invention of either.
Corrections are welcome
If you work on one of these products and we have a row wrong, tell us and we will fix it. Every row here is meant to be checkable against your own public documentation.
Send a correction