tari-project / tari / 26581360379

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push

github

Committed by web-flow

Commit Message

feat(wallet): stealth-address claim key for L1->L2 burns (#7861)

## Summary

Wallet-level implementation of the L1 half of
[tari-project/tari-ootle#1890](https://github.com/tari-project/tari-ootle/issues/1890)
— switches L1→L2 burn claims from "on-chain claim key = recipient's L2
account pubkey" to a stealth address scheme.

No L1 or L2 consensus changes; only L1 wallet behaviour. Matching L2
verifier/wallet changes will land separately in `tari-ootle`.

### What changes

- The on-chain `ConfidentialOutputData.claim_public_key` now carries the
stealth address `C = H(r·P)·G + P` instead of the recipient's pubkey
`P`. `C` looks like a random nonce per burn and is unlinkable to `P`
across burns; for the L2 wallets that want it, the on-chain value is
also a discoverability signal (`C` derivable from the on-chain `R` + the
account's `p`).
- The mask-key ownership signature commits to `H(commitment ‖ C)`. A
third party holding the proof material cannot construct an L2 claim —
only the L2 wallet holding `p` can derive the spend secret `s = H(R·p) +
p` against `C`.
- `SideChainFeature` is still emitted for L2-bound burns;
`sidechain_deployment_key` (when provided) still produces the
`SideChainId` Schnorr sig identifying the target L2 network. The
original "deployment key without claim public key" sanity check is
preserved.
- `sender_offset` key for L2-bound burns is seed-deterministic (derived
from the commitment mask). Plain burns keep `get_random_key`.
- `encrypted_data` for L2-bound burns is encrypted to `DH(P, r)`
(unchanged) so the existing L2 decryption with `DH(R, p)` keeps working.
Plain burns encrypt to the L1 view key.
- `PartialBurnClaimProof` wire shape is unchanged: `claim_public_key`
still carries `P`, `sender_offset_public_key` carries `R`. `C` is not on
the wire — both L1 and L2 recompute it from `(R, P, p)` (the L2 already
has `owner_stealth_dh_stealth_address` for this in
`dan/crates/wallet/crypto/src/kdfs.rs`).
- New key-manager helpers: `... (continued)

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