# age-over-v1: key ceremony transcript

Everything below is also in `circuit.json` (field `ceremony`). Times are UTC.

| | |
|---|---|
| Circuit | `age-over-v1` = zk-kit `range_b16_n` (range, {"bits":16,"nonce":true}), 321 constraints |
| circuitId | `0xf88cc3077af352474814c6a6ced1355060cd8986a058b0c8bd310528157d8da7` = keccak256("age-over-v1") |
| Public signals | `commitment`, `min`, `max`, `nonce` |
| vkHash | `0x7195c702a1711955b672f960a0bf2402420707678cf86d63595aec79e259d8f5` = keccak256(JCS(verification_key.json)) |
| ceremonyContributions (registry) | 1 |

## Phase 1: public Powers of Tau

The PSE Perpetual Powers of Tau (80 participants, closed with a pre-announced Ethereum randao
beacon), response 0080 prepared for phase 2 and truncated to 2^13.

| | |
|---|---|
| URL | https://pse-trusted-setup-ppot.s3.eu-central-1.amazonaws.com/pot28_0080/ppot_0080_13.ptau |
| Size | 9,530,514 bytes |
| blake2b-512 | `bf0c2d498f1197ad04ec0dbfcdda6df6348cbd793759f1f986e5cdf1a4100842293dfad6b8961f64b7ba35c162b5c821c4c097a52f3a639b55b0e765ec311b44` |
| sha256 | `ccee28086e4b81d81a6e16fdee054d1dbd5276362e2662d4205d31de45cb930f` |
| Header power | 2^13 (read from the file header) |
| S3 ETag | `bb54c403a93fabdabb99520b9fd94f56-2` (last modified Tue, 09 Apr 2024 07:06:01 GMT); multipart ETag recomputed with 8 MiB parts: matches |
| Downloaded | 2026-09-27T02:44:12.606Z |

PSE publishes no hash list for the prepared files, so the checks above are what could be made: the
header, the byte count, and the S3 multipart ETag recomputed from the bytes (a transport check, not
an authenticity check). snarkjs's full powers-of-tau verification was not run: it did not finish in
10 minutes even for the 2^8 file on the build machine. Download the file yourself and compare the
blake2b-512 before you rely on it.

## Phase 2

1. **Initial key** `_0000` = snarkjs `zkey new` of `age-over-v1.r1cs` on the phase-1 file. It is
   deterministic; anyone can recreate it (196,384 bytes, blake2b-512
   `b8527be6b115bb67ebb735f2c43abeb0925abaa2951064876a888f76a1ec041fa09c06410e1ba7f1c8426aba20da116519e355892f43cab8607cc8bc60a875bb`).
2. **Contribution #1: Super Wallet (SeoulLabs) phase-2 contribution**, 2026-09-27T02:44:16.188Z to 2026-09-27T02:44:16.263Z.
   Contribution hash:

   ```
   09e4f1b7a25334c06d3d91c025b4e173c3f29949988217166fb755f9eaf08785628732c5ea9421c33b0830d28dc62f685db09463e993390da91bd25cb12d5c89
   ```

   Entropy: 64 bytes from the operating system CSPRNG (`node:crypto` randomBytes), passed in
   memory to snarkjs, which mixes in its own random bytes. It was not written to disk, a log or a
   terminal, and the process has exited. All six production circuits were contributed in one run
   that finished at 2026-09-27T02:44:49.737Z.
3. **Beacon.** The rule, fixed in `zk-kit/scripts/production-ceremony.ts` before the run: after
   every contribution has finished, take the latest Xphere mainnet block whose timestamp is later
   than that moment, and apply its hash with 2^10 iterations (snarkjs `zkey beacon`).

   | | |
   |---|---|
   | Chain | Xphere mainnet, chain id 20250217 (read from https://en-hkg.x-phere.com) |
   | Block | 49677068 |
   | Block hash | `0x004d454b466cfbe88eedad46ef160b140124683eab1432b108a54b3111fac37a` |
   | Block time | 2026-09-27T02:44:58.000Z (fetched 2026-09-27T02:44:57.539Z) |
   | Iterations | 2^10 |
   | Beacon contribution hash | `99e833ac6f1444a59d8baa6222032704245829a7ae35392fb0464cc126997d31c7339e954c042a1d63da23240d801287335db12572f3d473b421d4c7d6fcc8ab` |

   Check the block: `curl -s -X POST -H 'content-type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["0x2f6030c",false]}' https://en-hkg.x-phere.com`
   and compare `hash`, or open https://xp.tamsa.io/block/49677068.

## What this ceremony does and does not give you

A Groth16 phase 2 is sound if **at least one** contributor destroyed their randomness. This key has
**one** contributor, Super Wallet, so its soundness rests on Super Wallet having done so. The public
beacon makes the final key depend on a value nobody knew when the contribution was made, but it is
public and adds no secret: it does not replace a second, independent contributor. The block number
was not announced in advance; the rule for picking it was fixed in the script, and the block came
after the contribution. The registry records `ceremonyContributions = 1` as it is.

**An institution that wants to add its own contribution** takes `age-over-v1.zkey` (this key; the
contribution chain inside it continues), checks it with `zk-kit verify-ceremony`, runs
`zk-kit contribute`, and hands the result back; Super Wallet then applies a new, pre-announced
beacon with `zk-kit finalize`. The result is a new key and therefore a new circuit id,
`age-over-v2`, registered alongside this one with ceremonyContributions = 2. A
key is never swapped in under an existing circuit id.

## Result

| | |
|---|---|
| verifyFromR1cs (r1cs + phase-1 file + zkey) | OK |
| Circuit hash (snarkjs) | `1f343a85bbfb48a1bbd86c2600a15cc5998deb02082bb1063f209405d3be8665e38105daea204dda1a26871ab42f2a6022e15f850d9ac4d29e296d89c17a6e52` |
| `age-over-v1.zkey` | 197,289 bytes, sha256 `3dde33bb5efe9e030962f731a3849ae1b4d0c0d7d590a7cb046ce4a685a38aba`, blake2b-512 `6c8f0e2d34aadb83a6fb6a612a5e12270a284e91ebf9985c80f41960b37e745fe960ea298c282e5444535390093abc8093fc91cec37dcc2b7ace211febf9e6c2` |
| `age-over-v1.r1cs` | 130,344 bytes, sha256 `2f32f5d7bb3c5f53396cce353362f0c5e2da5fda9455ada783bdaa6c8b6f3694` |
| `age-over-v1.wasm` | 1,753,948 bytes, sha256 `951cf295d2d3a5e67743d39d8dc72d7e17e7b241880174c6b6e2d24301a6bf0a` |
| vkHash | `0x7195c702a1711955b672f960a0bf2402420707678cf86d63595aec79e259d8f5` |
| Verifier.sol runtime keccak256 (solc 0.8.24, optimizer 200, paris) | `0xa03d7f7b30cbefe3ed6a91590f735d9648c7487d252769bbe6d4c410935532fc` |

## Check it yourself

```sh
npm install /path/to/zk-kit          # or: npm install snarkjs@0.7.6 and use snarkjs directly
npx zk-kit ptau --power 13 --public --out ppot_0080_13.ptau   # compare blake2b512 above
npx zk-kit verify-ceremony --r1cs age-over-v1.r1cs --ptau ppot_0080_13.ptau --zkey age-over-v1.zkey
# prints: zkey VALID, then #1 Super Wallet (SeoulLabs) phase-2 contribution: 09e4f1b7a25334c0...
#                             #2 Xphere mainnet block 49677068 beacon [beacon 004d454b466cfbe8..., 2^10 iterations]
```