To eliminate redundant transfers over WAN links and improve network efficiency, middleboxes have been deployed at ingress/egress. These middleboxes can operate on individual packets and are application layer protocol transparent. They can identify and remove duplicated byte strings on the fly. However, with the increasing use of HTTPS, current redundancy elimination (RE) solution can no longer work without violating end-to-end privacy. In this paper, we present RE over encrypted traffic (REET), the first middlebox-based system that supports both intra-user and inter-user packet-level RE directly over encrypted traffic. REET realizes this by using a novel protocol with limited overhead and protects end users from honest-but-curious middleboxes. We implement REET and show its performance for both end users and middleboxes using several hundred gigabytes of network traffic traces collected from a large U.S. university.