Traffic monitoring is essential for network management tasks that ensure
security and QoS. However, the continuous increase of HTTPS traffic undermines
the effectiveness of current service-level monitoring that can only rely on
unreliable parameters from the TLS handshake (X.509 certificate, SNI) or must
decrypt the traffic. We propose a new machine learning-based method to identify
HTTPS services without decryption. By extracting statistical features on TLS
handshake packets and on a small number of application data packets, we can
identify HTTPS services very early in the session. Extensive experiments
performed over a significant and open dataset show that our method offers a
good accuracy and a prototype implementation confirms that the early
identification of HTTPS services is satisfied.