KEMTLS

Conference presentation of our KEMTLS formal analysis paper at ESORICS 2022

A tale of two models: Formal analysis of KEMTLS in Tamarin Sofía Celi, Jonathan Hoyland, Douglas Stebila and Thom Wiggers. Once upon a time... Observation: PQ signatures are quite big and/or slow Idea: Use KEMs for authentication Proposal: KEMTLS KEMTLS sequenceDiagram Client->>+Server: ClientHello: ephemeral kex Server->>-Client: ServerHello: ephemeral kex Server->>+Client: Certificate: static KEM pk Client->>-Server: Ciphertext Client->>Server: ClientFinished rect rgba(0, 0, 0, 0) Client-->>Server: Application Data end Server->>Client: ServerFinished Server-->>Client: Application Data sequenceDiagram Client->>+Server: ClientHello: ephemeral kex Server->>-Client: ServerHello: ephemeral kex Server->>+Client: Certificate: static KEM pk Client->>-Server: Ciphertext Client->>Server: ClientFinished rect pink Client-->>Server: Application Data end Server->>Client: ServerFinished Server-->>Client: Application Data Ephemeral KEM key exchange KEM public key in certificate Avoid extra round-trip by letting client send data immediately KEMTLS variants Mutual authentication What if the client already knows the server's public key?

We prove the security of KEMTLS in two Tamarin models. One mode is based on the Cremers et al. model of TLS 1.3; the other closely resembles our pen-and-paper proofs. These models allow us to analyse KEMTLS, and its extension KEMTLS-PDK from different angles.

Invited lecture about TLS, its history and making TLS post quantum. I also discuss KEMTLS.

KEMTLS (CCS 2020) is a novel alternative to the Transport Layer Security (TLS) handshake that integrates post-quantum algorithms. It …

We make KEMTLS more efficient in scenarios where the client already has the server’s long-term public key, for example through caching or because it’s pre-installed.

Talk about KEMTLS on Cloudflare TV

Talk about Post-Quantum TLS without Handshake Signatures at RWC 2021 (virtual).

Conference talk about Post-Quantum TLS without Handshake Signatures at ACM CCS (virtual).