# adverse-loans-max-v1: key ceremony transcript

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

| | |
|---|---|
| Circuit | `adverse-loans-max-v1` = zk-kit `range_b8_n` (range, {"bits":8,"nonce":true}), 281 constraints |
| circuitId | `0x69484b162813af9a662f7a34cdfbafb17be1d322cf77e04b0dd5cf6cbea53a47` = keccak256("adverse-loans-max-v1") |
| Public signals | `commitment`, `min`, `max`, `nonce` |
| vkHash | `0x36c49b3256f286f2b2672a1982f09cb542bacf554f91b679b33caa0246816bac` = 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 2^9.

| | |
|---|---|
| URL | https://pse-trusted-setup-ppot.s3.eu-central-1.amazonaws.com/pot28_0080/ppot_0080_09.ptau |
| Size | 683,154 bytes |
| blake2b-512 | `33ccbcacd7c43238b540f8dd7f68b4acac6be3a1fe2e695d55aea291172d30ddc8056c2851f5660b5e795550f300660042072254813d1558dc4d5a7192eae9b6` |
| sha256 | `67e59e346767e179a5bd88b4789a56ce376708244c01a32b520ee208dbfb2595` |
| Header power | 2^9 (read from the file header) |
| S3 ETag | `69d89d14fb047514a1eb6c82ffd5a718` (last modified Tue, 09 Apr 2024 07:02:55 GMT); md5 matches |
| Downloaded | 2026-09-27T06:12:41.730Z |

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 `adverse-loans-max-v1.r1cs` on the phase-1 file. It is
   deterministic; anyone can recreate it (174,784 bytes, blake2b-512
   `30da171bbbfdab3fd987561af258532841e96cbbc82e9742d81ff5e6bab807d3e0dc2bb0b6dd340ab72e96f0f6704f90a0f957af10932c6554f882b73eebd355`).
2. **Contribution #1: Super Wallet (SeoulLabs) phase-2 contribution**, 2026-09-27T06:12:54.019Z to 2026-09-27T06:12:54.094Z.
   Contribution hash:

   ```
   51fd2cc15de1b87345cabf420128e1eb7aa210f0f39b69cb9f76e764b10fa2552b5bdcab45bb4c5d56f463edd9a951bf766bd561fe077c412e66e7e9f98a0fc3
   ```

   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 seven circuits of ceremony batch 2 were contributed in one
   run that finished at 2026-09-27T06:13:03.218Z.
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 | 49689564 |
   | Block hash | `0xf881b8862fb95d63b2269b5a6e6ae228156d78250e72c9c7129901b460d820de` |
   | Block time | 2026-09-27T06:13:14.000Z (fetched 2026-09-27T06:13:13.528Z) |
   | Iterations | 2^10 |
   | Beacon contribution hash | `27efea6fe2b8df6fcb8a5f4e9b7cfc26098b36015135e540f3dc5897750223e864f49ca0dc4ff88a68e7858e9cb72b0761b3827f1858a8aa558e4e111e7d5e32` |

   Check the block: `curl -s -X POST -H 'content-type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["0x2f633dc",false]}' https://en-hkg.x-phere.com`
   and compare `hash`, or open https://xp.tamsa.io/block/49689564.

## 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 `adverse-loans-max-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,
`adverse-loans-max-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) | `f383fd4e11dc6b9f916543f1ab8ab1d7c27b238d26f22ff18f28ec1af1d3816724461f37ca9314ddc80c495a69fa949a5b1c976c376da0440bab2a4db850aac6` |
| `adverse-loans-max-v1.zkey` | 175,689 bytes, sha256 `6b780eacb98833f4645cef8eb5bdf874f07f1ec1b7a8b621ed59ec3da82c3848`, blake2b-512 `bba94dd4a01c74bcd7d0b9b15eb3de4c8017416399c208f0605d78d4fe802663126e56bc893d073553ce43629e895917051616701510fb63c62a9105fdb9df16` |
| `adverse-loans-max-v1.r1cs` | 122,344 bytes, sha256 `20b490b76247b339ae1666590ec153213ae4e432da4be4c400e75037931ad1fc` |
| `adverse-loans-max-v1.wasm` | 1,753,703 bytes, sha256 `844c68355c65d3d077f9100fa0168316dc411ac6df433e153d2303618aee9c3e` |
| vkHash | `0x36c49b3256f286f2b2672a1982f09cb542bacf554f91b679b33caa0246816bac` |
| Verifier.sol runtime keccak256 (solc 0.8.24, optimizer 200, paris) | `0x5340ab2b4bd858b53c5c951b15c1f108fdd605b1f447ffedc51519a6e2f08859` |

## 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 9 --public --out ppot_0080_9.ptau   # compare blake2b512 above
npx zk-kit verify-ceremony --r1cs adverse-loans-max-v1.r1cs --ptau ppot_0080_9.ptau --zkey adverse-loans-max-v1.zkey
# prints: zkey VALID, then #1 Super Wallet (SeoulLabs) phase-2 contribution: 51fd2cc15de1b873...
#                             #2 Xphere mainnet block 49689564 beacon [beacon f881b8862fb95d63..., 2^10 iterations]
```