How deeply does Real-World Cryptography cover EdDSA?

Explains deterministic nonce generation, derived keys, curve choices, and the Schnorr relationship without descending into implementation details.

EdDSA

As explained in Real-World Cryptography

EdDSA is a deterministic public-key digital signature algorithm based on Schnorr signatures over twisted Edwards curves.

EdDSA, or Edwards-curve Digital Signature Algorithm, is a deterministic public-key signature scheme based on Schnorr signatures and twisted Edwards curves. It was designed for practical applications and has gained broad adoption. section 7.3 section 7.3.4

A signing operation follows a deliberately derived-key design:

EdDSA starts with a secret key rather than generating the signing key directly. section 7.3.4
The secret key derives both the actual signing key and a nonce key; the signing key derives the public key. section 7.3.4
The nonce key deterministically produces the per-signature nonce from the message, so signing does not require fresh randomness each time. section 7.3.4

Ed25519 and Ed448

RFC 8032 defines EdDSA with two twisted Edwards curves. Ed25519 combines EdDSA with Edwards25519 and provides 128-bit security; Ed448 uses Edwards448 and provides 224-bit security. In practice, Ed25519 is the common instantiation. section 7.3.4 section 7.5

How Real-World Cryptography covers it

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Related concepts

ECDSAcontrasts with · ECDSA is a public-key digital signature algorithm that uses elliptic-curve arithmetic to generate and verify signatures.
Schnorr signatureuses · A Schnorr signature is a public-key digital signature scheme based on a proof of knowledge of a discrete logarithm.
Ed25519includes · Ed25519 is an EdDSA public-key digital signature scheme based on a twisted Edwards curve over a 255-bit prime field.
digital signaturekind of · A digital signature is cryptographic data generated with a private key and verified with corresponding public information to authenticate data or its signer and detect alteration.

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