The goal of the International Workshop on Security Proofs for Embedded Systems (PROOFS) is to promote methodologies that increase the confidence level in the security of embedded systems. Formal methods for verification and safety are used in several related fields, such as software; however, the security of embedded systems, including cryptographic hardware and software, is often challenged by many attacks, particularly at the implementation level. Strategies to secure embedded systems are known, but they need to be implemented with care. The main objective of the PROOFS workshop is to bridge the gap between both topics and thus pave the way to verifiable security by design for embedded systems. The workshop is an opportunity for researchers of different fields to exchange on their work and also to present some innovative use-cases and/or proofs of concept. The fifth edition of the PROOFS workshop was held on Saturday August 20, 2016, at Santa Barbara in USA. As all previous editions, PROOFS workshop was scheduled the day after CHES (Cryptographic Hardware and Embedded Systems), the flagship IACR conference on embedded systems security. The PROOFS Workshop 2016 featured two invited talks. Yuval Yarom (from The University of Adelaide and Data61, Australia) gave a talk on the following topic:Thwarting cache-based side-channel attacks. Ryan Kastner (from University of California, San Diego, USA) talked aboutMoving Hardware from “Security through Obscurity” to “Secure by Design”.