Serve pow-puzzles through RPC API

[Sword-Smith]

Allow users to get PoW puzzles where they provide the guesser digest. We'd need a new RPC endpoint for this.

[jan-ferdinand]

I'm unsure how this ties into the explorer. Should this perhaps be an issue on neptune-core? Otherwise, I'm looking forward to being enlighted. 💡

[Sword-Smith]

It was intended to be added here, not to neptune-core. The idea is that a guesser can send an HTTP/JSON request to the block explorer and get the cryptographic data required to start guessing, i.e. attempting to solve the PoW puzzle.

The data required to start guessing is contained in the struct ProofOfWorkPuzzle in neptune-core. Through the endpoint pow_puzzle_external_key, the guesser can supply their own guesser digest and get the matching puzzle which, if they solve, would reward the guesser fraction of the coinbase to them.

/// Data required to attempt to solve the proof-of-work puzzle that allows the
/// minting of the next block.
#[derive(Clone, Debug, Copy, Serialize, Deserialize)]
pub struct ProofOfWorkPuzzle {
    // All fields public since used downstream by mining pool software.
    pub kernel_auth_path: [Digest; BlockKernel::MAST_HEIGHT],
    pub header_auth_path: [Digest; BlockHeader::MAST_HEIGHT],

    /// The threshold digest that defines when a PoW solution is valid. The
    /// block's hash must be less than or equal to this value.
    pub threshold: Digest,

    /// The total reward, timelocked plus liquid, for a successful guess.
    pub total_guesser_reward: NativeCurrencyAmount,

    /// An identifier for the puzzle. Needed since more than one block proposal
    /// may be known for the next block. A commitment to the entire block
    /// kernel, apart from the nonce.
    pub id: Digest,

    /// Indicates whether template is invalid due to the presence of a new tip.
    /// Can be used to reset templates in pools that perform local checks before
    /// submitting a solution to the node.
    pub prev_block: Digest,
}

[aszepieniec]

The idea is that a guesser can send an HTTP/JSON request to the block explorer and get the cryptographic data required to start guessing, i.e. attempting to solve the PoW puzzle.

How is that better or more preferable to sending a RPC request to a node that the guesser is running?