9.4 Cryptographic Foundations

PTERI relies only on well-established cryptographic primitives.

There are no experimental algorithms.

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Key Generation & Signing

• Elliptic Curve Cryptography (secp256k1)

• Hardware-backed key storage where available

• Keys are generated locally on the device

• Private keys are non-exportable

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Challenge–Response Authentication

• Cryptographically random nonces

• Explicit expiration windows

• Single-use enforcement

• Deterministic verification

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Transaction Verification

• Litecoin proof-of-work consensus

• UTXO-based validation

• Optional MWEB privacy guarantees

• Public, independently verifiable settlement

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Hashing & Integrity

• Cryptographic hash functions for message integrity

• Signed payloads are tamper-evident

• Any modification invalidates verification

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