I. Introduction
This paper concerns the problem of fast and accurate classification of encrypted traffic (such as TLS (Transport Layer Security) traffic). Network traffic classification, the task of associating network traffic with the application protocol or the application that generates it, is crucial for network management and network security [1], [2], [3], [4], [5], [6]. Network management often requires the quick and accurate classification of TCP/UDP flows according to their application categories, so as to achieve hierarchical management of network traffic, and provide Internet users with better quality of service assurance. For network security, traffic classification is often the first step to filter normal network traffic and find network anomalies. For example, quality of service (QoS) [6] and network anomaly detection [1], [4] require fast and accurate network traffic classification.