Cryptology ePrint Archive: Report 2020/1044

A Cryptographic Analysis of the TLS 1.3 Handshake Protocol

Benjamin Dowling and Marc Fischlin and Felix Günther and Douglas Stebila

Abstract: We analyze the handshake protocol of the Transport Layer Security (TLS) protocol, version 1.3. We address both the full TLS 1.3 handshake (the one round-trip time mode, with signatures for authentication and (elliptic curve) Diffie–Hellman ephemeral ((EC)DHE) key exchange), and the abbreviated resumption/"PSK" mode which uses a pre-shared key for authentication (with optional (EC)DHE key exchange and zero round-trip time key establishment). Our analysis in the reductionist security framework uses a multi-stage key exchange security model, where each of the many session keys derived in a single TLS 1.3 handshake is tagged with various properties (such as unauthenticated versus unilaterally authenticated versus mutually authenticated, whether it is intended to provide forward security, how it is used in the protocol, and whether the key is protected against replay attacks). We show that these TLS 1.3 handshake protocol modes establish session keys with their desired security properties under standard cryptographic assumptions.

Category / Keywords: cryptographic protocols / key exchange; Transport Layer Security protocol; TLS 1.3

Original Publication (in the same form): IACR-JOC-2021

Date: received 28 Aug 2020

Contact author: dstebila at uwaterloo ca

Available format(s): PDF | BibTeX Citation

Version: 20200828:185240 (All versions of this report)

Short URL: ia.cr/2020/1044


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