Mezzo TLS 1.3 Protocol, Suitable for Transmitting Already-Encrypted Data

Abstract

Secure communication protocols such as TLS 1.3 are used almost everywhere to protect the confidentiality and integrity of data in transit. The encryption part in these protocols does not come for free: it adds latency and consumes processing cycles. Although nowadays, modern computing platforms encrypt data very efficiently, the encryption overheads can be spared when they are not required. For example, if an application store the data in an encrypted form, transferring it under TLS 1.3 involves double encryption (and decryption) of the date without adding privacy. Specifically, consider homomorphic encryption based applications or encrypted databases. This paper introduces ``Mezzo-TLS 1.3", which is a version of TLS 1.3 that is suitable for already- encrypted inputs. We show that when the threat model allows for using Mezzo-TLS 1.3, this protocol can speed up data transfer by up to $2.58\times$.