Two-Party MLS Secure Channels With Reduced Handshake Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Messaging Layer Security Protocol (MLS) has significant overhead in one-to-one (two-party) secure channel scenarios compared to other two-party secure channel protocols, leading to inefficiencies and increased complexity.
Innovation Solution
A modified version of the MLS protocol, referred to as 2MLS, is introduced to reduce communication and computation overhead in two-party scenarios by incorporating a minimal set of changes, enabling efficient secure channel establishment with features like post-quantum security, symmetric endpoint treatment, and support for synchronous and asynchronous operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MLS protocol is used for one-to-one secure channel establishment, then security features such as forward secrecy and post-compromise security are achieved, but communication and computation overhead increases significantly
Solution Approach 1:
The protocol is segmented into two distinct modes: 2MLS mode for two-party communication and MLS mode for group communication. This segmentation allows each mode to be optimized independently, enabling 2MLS to reduce overhead for one-to-one channels while preserving the full functionality of MLS for groups.
Solution Approach 2:
The protocol dynamically adapts its behavior based on the number of participants. When only two parties are communicating, it activates the streamlined 2MLS path with reduced message exchanges and simplified key derivation. When three or more parties join, it automatically transitions to the full MLS protocol, making the system flexible and efficient across different scenarios.
2Reliability
If the MLS protocol is used for one-to-one communication, then security features are maintained, but communication efficiency decreases
Solution Approach 1:
The 2MLS mode extracts and removes the redundant components from the MLS protocol that are only necessary for group communication. This includes eliminating unnecessary key derivation steps, simplifying the message structure, and removing features specific to multi-party scenarios, thereby achieving higher communication efficiency for one-to-one channels.
Solution Approach 2:
The protocol changes key parameters when operating in 2MLS mode versus full MLS mode. These parameter changes include the number of handshake messages, the complexity of key derivation functions, and the structure of cryptographic exchanges, all optimized for two-party communication to improve productivity while maintaining security.
3Reliability
If the MLS protocol is used for one-to-one communication, then security features are achieved, but protocol complexity increases
Solution Approach 1:
The protocol is segmented into two distinct modes: 2MLS mode for two-party communication and MLS mode for group communication. This segmentation allows each mode to be optimized independently, enabling 2MLS to reduce overhead for one-to-one channels while preserving the full functionality of MLS for groups.
Solution Approach 2:
The protocol introduces asymmetry in its design by treating two-party and group scenarios differently. The 2MLS mode uses asymmetric optimizations tailored for pairwise communication, such as simplified key derivation and reduced message types, while the full MLS protocol maintains symmetry for group scenarios, reducing overall protocol complexity for each specific use case.
Data Source
AI summary
Presented herein is a Message Layer Security (MLS)-based secure channel communication arrangement that involves a minimal set of changes to the MLS standard to reduce the redundant overhead in case of two-party (one-to-one or 1:1) communication. These techniques reduce the communication and computation complexity of both devices involved in establishing and supporting the one-to-one secure channel communication. Methods are provided to establish a one-to-one secure channel between a first endpoint and a second endpoint by performing a one-to-one secure channel handshake.