/// First 64 bytes of the BLAKE2s input during group hash.
/// This is chosen to be some random string that we couldn't have anticipated when we designed
/// the algorithm, for rigidity purposes.
/// We deliberately use an ASCII hex string of 32 bytes here.
pub const GH_FIRST_BLOCK: &'static [u8; 64]
          = b"0000000000000000002ffe76b973aabaff1d1557d79acf2c3795809c83caf580";

// BLAKE2s invocation personalizations
/// BLAKE2s Personalization for CRH^ivk = BLAKE2s(ak | nk)
pub const CRH_IVK_PERSONALIZATION: &'static [u8; 8]
          = b"Zcashivk";

/// BLAKE2s Personalization for PRF^nf = BLAKE2s(nk | rho)
pub const PRF_NF_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_nf";

// Group hash personalizations
/// BLAKE2s Personalization for Pedersen hash generators.
pub const PEDERSEN_HASH_GENERATORS_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_PH";

/// BLAKE2s Personalization for the group hash for key diversification
pub const KEY_DIVERSIFICATION_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_gd";

/// BLAKE2s Personalization for the spending key base point
pub const SPENDING_KEY_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_G_";

/// BLAKE2s Personalization for the proof generation key base point
pub const PROOF_GENERATION_KEY_BASE_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_H_";

/// BLAKE2s Personalization for the note commitment randomness generator
pub const NOTE_COMMITMENT_RANDOMNESS_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcashrcm";

/// BLAKE2s Personalization for the value commitment randomness generator
pub const VALUE_COMMITMENT_RANDOMNESS_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcashrcv";

/// BLAKE2s Personalization for the value commitment generator for the value
pub const VALUE_COMMITMENT_VALUE_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcash_cv";

/// BLAKE2s Personalization for the nullifier position generator (for computing rho)
pub const NULLIFIER_POSITION_IN_TREE_GENERATOR_PERSONALIZATION: &'static [u8; 8]
          = b"Zcashrho";