How deeply does Real-World Cryptography cover authenticated key exchange?

Explains passive and active attacks, one-sided and mutual authentication, signatures, and verification failure, but avoids formal protocol proofs.

Authenticated key exchange

As explained in Real-World Cryptography

A key exchange protocol that authenticates at least one party to prevent an active man-in-the-middle attacker from impersonating that party.

An authenticated key exchange lets parties agree on a shared secret while authenticating at least one side. Without authentication, a passive MITM cannot derive the secret, but an active MITM can impersonate both parties by replacing their public keys. section 5.1 section 5.5

A one-sided authenticated exchange proceeds in clear stages:

The authenticated party generates a key-exchange key pair and sends its public key with authentication evidence. section 7.1.2
The other party verifies the evidence using a previously known public verifying key, then uses the key-exchange public key to derive a shared secret. section 5.1 section 7.1.2
If verification fails, the party aborts instead of accepting a potentially intercepted exchange. section 7.1.2

A time service

A time service can provision users with its public key rather than manually sharing a MAC key with every user. Users can authenticate the server’s side of each exchange, preventing an active MITM from impersonating the server. The client remains unauthenticated unless it also provides authentication; authenticating both sides creates a mutually authenticated key exchange. section 5.1 section 5.5

How Real-World Cryptography covers it

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Related concepts

mutually authenticated key exchangeincludes · A mutually authenticated key exchange is an authenticated key exchange in which both participants authenticate each other while establishing a shared secret.
key exchangekind of · Key exchange is a cryptographic protocol by which communicating parties establish a shared secret over a communication channel without directly transmitting that secret.
digital signatureuses · 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.
man-in-the-middle attackaddresses · A man-in-the-middle attack is a network attack in which an adversary intercepts, relays, impersonates, or alters communication between parties.

This explainer was generated by Manning's knowledge graph from the text of Real-World Cryptography. The section links point to the parts of the book it draws on.