Plutus.V1.Ledger.Crypto

• 1. 📜 Overview

• 2. 🔧 LANGUAGE EXTENSIONS AND IMPORTS

• 3. 🗄️ Data Structures

  • 3.1 🔑 PubKeyHash (newtype)

• 4. 🤝 Typeclass Instances

• 5. 🏭 On‑chain Derivations

• 6. 📚 Glossary

---

1 📜 Overview

The Plutus.V1.Ledger.Crypto module introduces the PubKeyHash type, a lightweight wrapper around a built‑in byte string used to identify public keys on‑chain.

It covers:

• A zero‑cost newtype for public key hashes

• Derivations for on‑chain and off‑chain typeclasses (Eq, Ord, ToData, etc.)

• IsString and pretty printing via LedgerBytes

• On‑chain lifting with makeLift

---

2 🔧 LANGUAGE EXTENSIONS AND IMPORTS

{-# LANGUAGE DataKinds         #-}
{-# LANGUAGE DeriveAnyClass    #-}
{-# LANGUAGE DeriveGeneric     #-}
{-# LANGUAGE DerivingVia       #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell   #-}
{-# LANGUAGE TypeApplications  #-}

{-# OPTIONS_GHC -fno-omit-interface-pragmas #-}

module Plutus.V1.Ledger.Crypto (
    PubKeyHash(..)
    ) where

import Control.DeepSeq (NFData)
import Data.String (IsString)
import GHC.Generics (Generic)
import Plutus.V1.Ledger.Bytes (LedgerBytes(..))
import PlutusTx qualified
import PlutusTx.Lift (makeLift)
import PlutusTx.Prelude qualified as PlutusTx
import Prettyprinter (Pretty)

• LANGUAGE pragmas:

  • DataKinds, DeriveAnyClass, DeriveGeneric, DerivingVia, OverloadedStrings, TemplateHaskell, TypeApplications

• OPTIONS_GHC: suppresses interface pragma omissions.

• Imports:

  • NFData and Generic for deep evaluation and generics.

  • IsString for string literal conversion via LedgerBytes.

  • PlutusTx modules for on‑chain typeclasses and utilities.

  • Prettyprinter for human‑readable instances.

---

3 🗄️ Data Structures

3.1 🔑 PubKeyHash (newtype)

newtype PubKeyHash = PubKeyHash { getPubKeyHash :: PlutusTx.BuiltinByteString }
    deriving stock    (Eq, Ord, Generic)
    deriving anyclass (NFData)
    deriving newtype (PlutusTx.Eq, PlutusTx.Ord, PlutusTx.ToData, PlutusTx.FromData, PlutusTx.UnsafeFromData)
    deriving IsString via LedgerBytes
    deriving (Show, Pretty) via LedgerBytes

• Field: getPubKeyHash unwraps the underlying BuiltinByteString.

• Deriving strategies: separates stock, anyclass, newtype, and via approaches.

Example usage:

let pkh = "aabbcc" :: PubKeyHash  -- via IsString
print pkh                       -- via Pretty (hex display)

---

4 🤝 Typeclass Instances

• Eq, Ord (stock) for equality and ordering.

• NFData (anyclass) for deep evaluation.

• PlutusTx.Eq, PlutusTx.Ord, PlutusTx.ToData, PlutusTx.FromData, PlutusTx.UnsafeFromData (newtype) for on‑chain serialization and comparison.

• IsString (via LedgerBytes) to parse hex string literals.

• Show, Pretty (via LedgerBytes) to display as hex text.

---

5 🏭 On‑chain Derivations

makeLift ''PubKeyHash

• makeLift: generates the Lift instance allowing embedding of PubKeyHash values in PlutusTx code.

---

6 📚 Glossary

• PubKeyHash: hashed public key identifier for on‑chain use.

• BuiltinByteString: Plutus’s representation of raw bytes.

• newtype: zero‑cost Haskell wrapper for a single field.

• DerivingVia: uses an existing type’s instances (LedgerBytes) to derive for a new type.

• IsString: typeclass for conversion from string literals.

• makeLift: Template Haskell function to create Lift instances for on‑chain embedding.

• PlutusTx.ToData / FromData: on‑chain serialization for BuiltinData.

• NFData: class for deep (normal form) evaluation.

• Pretty: pretty‑printing class from Prettyprinter.