arXiv subjects

Xinshu Ma

Publications and source records attributed to Xinshu Ma.

3 recordsLinked to original sources

arXiv2026

Designing Transport-Level Encryption for Datacenter Networks

Cloud applications need network data encryption to isolate from other tenants and protect their data from potential eavesdroppers in the network infrastructure. This paper presents SMT, a protocol design for emerging datacenter transport protocols, such as NDP and Homa, to integrate data encryption. SMT integrates TLS-based encryption with a message-based transport protocol that supports efficient Remote Procedure Calls (RPCs), a common workload in datacenters. This architecture enables the use of per-message record sequence number spaces in a secure session, while ensuring unique message identities to prevent replay attacks. It also enables the use of existing NIC offloads designed for TLS over TCP, while being a native transport protocol alongside TCP and UDP. We implement SMT in the Linux kernel by extending Homa/Linux and improve RPC throughput by up to 41 % and latency by up to 35 % in comparison to TLS/TCP.

cs.CR↗

arXiv2023

VeraSel: Verifiable Random Selection for Mixnets Construction

The security and performance of Mixnets depends on the trustworthiness of the Mixnodes in the network. The challenge is to limit the adversary's influence on which Mixnodes operate in the network. A trusted party (such as the Mixnet operator) may ensure this, however, it is a single point of failure in the event of corruption or coercion. Therefore, we study the problem of how to select a subset of Mixnodes in a distributed way for Mixnet construction. We present VeraSel, a scheme that enables Mixnodes to be chosen according to their weights in a distributed, unbiased, and verifiable fashion using Verifiable Random Functions (VRFs). It is shown that VeraSel enables any party to learn and verify which nodes has been selected based on the commitments and proofs generated by each Mixnode with VRF.

cs.CR↗

arXiv2022

Stopping Silent Sneaks: Defending against Malicious Mixes with Topological Engineering

Mixnets provide strong meta-data privacy and recent academic research and industrial projects have made strides in making them more secure, performance, and scalable. In this paper, we focus our work on stratified Mixnets -- a popular design with real-world adoption -- and identify that there still exist heretofore inadequately explored practical aspects such as: relay sampling and topology placement, network churn, and risks due to real-world usage patterns. We show that, due to the lack of incorporating these aspects, Mixnets of this type are far more susceptible to user deanonymization than expected. In order to reason and resolve these issues, we model Mixnets as a three-stage ``Sample-Placement-Forward'' pipeline, and using the results of our evaluation propose a novel Mixnet design, Bow-Tie. Bow-Tie mitigates user deanonymization through a novel adaption of Tor's guard design with an engineered guard layer and client guard-logic for stratified mixnets. We show that Bow-Tie has significantly higher user anonymity in the dynamic setting, where the Mixnet is used over a period of time, and is no worse in the static setting, where the user only sends a single message. We show the necessity of both the guard layer and client guard-logic in tandem as well as their individual effect when incorporated into other reference designs. Ultimately, Bow-Tie is a significant step towards addressing the gap between the design of Mixnets and practical deployment and wider adoption because it directly addresses real-world user and Mixnet operator concerns.

cs.CR↗