Developer

SonoSig encoding standard.

SONOSIG1 is a portable audio-proof format that embeds a wallet-signed claim into an exported audio file while keeping the proof readable by browsers, agents, registries, and public identity systems.

Container header

Bytes	Meaning
0..7	ASCII magic string `SONOSIG1`.
8..11	Unsigned 32-bit little-endian payload length.
12..n	UTF-8 JSON proof payload. Current maximum: 16 KB.

1. Normalize the local audio

SonoSig decodes the source audio in the browser and works from PCM sample data. The source file is not uploaded just to create the proof.

2. Derive audio identifiers

The implementation computes sha256-based audio_hash and audio_fingerprint values from the normalized audio. These values bind the proof to a specific audio signal.

3. Build the SIWE-style message

SonoSig creates a deterministic message containing the wallet, chain, protocol, audio hash, audio fingerprint, nonce, timestamp, and optional ENS, manifest, and song metadata.

4. Sign with the creator wallet

The connected wallet signs the exact message. Verifiers must check the signature against that exact message and wallet address.

5. Embed SONOSIG1

SonoSig serializes the proof as JSON, prefixes it with a SONOSIG1 header and little-endian payload length, then embeds the bytes into the exported audio.

6. Verify and register

Verification extracts the payload, rebuilds the signed message, checks the signature, and compares the audio identifiers. Claims can then be registered with PacStac and pointed to from ENS.

Proof payload

v

Format version. Current value: 1.

protocol

Protocol identifier. Current value: audio-proof-v1.

wallet

EVM wallet address that signed the deterministic claim.

chain_id

EVM chain ID used in the signed message.

audio_hash

sha256:<64 hex chars> hash of the normalized PCM audio.

audio_fingerprint

sha256:<64 hex chars> derived audio fingerprint.

issued_at

ISO timestamp for claim creation.

nonce

Random nonce used to prevent replay.

signature_type

Signature scheme. Current value: SIWE.

signature

0x-prefixed wallet signature over the exact SIWE message.

ens

Optional ENS name associated with the creator wallet.

manifest

Optional URL or IPFS URI for richer claim metadata.

song

Optional title, artist, album, ISRC, and other song metadata.

PCM embedding

For WAV and AIFF exports, SonoSig embeds payload bits into the least significant bit of sequential 16-bit PCM samples. Each byte is written least-significant bit first. Verification reads the same sample sequence, reconstructs the header and payload, then validates the proof.

Compressed exports

For M4A and OGG exports, SonoSig appends the SONOSIG1 proof block to the encoded file bytes for portability. Exact audio-hash verification is strongest with PCM WAV and AIFF because lossy encoders can change sample data.

Registry and identity layers

PacStac verifies and indexes submitted SonoSig claims by claim ID, wallet, audio hash, audio fingerprint, and optional ISRC. ENS can publish a compact com.sonosig text record that points readers to the PacStac wallet collection for a creator name.