This work explores the feasibility of combining zero-knowledge proofs with SGX enclave protection technology, using the Hyperledger fabric, as the testing environment. The focus is on assessing the viability of this combination in real-world scenarios where post-quantum security is crucial. To this end, a new zero-knowledge proof, called Vesper, has been developed. This is a lattice-based zk-SNARK with a Regev commitment scheme. Vesper aims to provide a novel approach to developing lattice-based zero-knowledge proofs suitable for blockchain environments. Vesper features a proof size of 128 bytes, an average verification time of 0.14 ms, requires no trusted setup, while achieving at least 128-bit and 256-bit security. Only the proof geberation time increases when the LWE dimension increases. To analyze and explore the potential of combining Intel SGX with such a ZKP and Hyperledger Fabric, two projects have been developed: 1. Vesper Smart Contract: This project uses Vesper in combination with a lattice-based digital signing scheme that has been NIST-approved. The proof generation benefits from SGX enclave protection, while the verifier for Vesper is deployed in a permissioned blockchain as a smart contract. Middleware using Fabric Peer command line interface (CLI) tools facilitates commu- nication between the prover and verifier sides. 2. Vesper-FPC: This project explores the feasibility of protecting Hyperledger Fabric chaincode with an SGX enclave. It combines Vesper with a simplified lattice-based digital signing function to accommodate a restricted environment. Both the proof generation and the deployed verifier are SGX-protected. Communication is managed via custom peer CLI commands specifically de- signed to handle the interaction between the additional SGX protection layer and the blockchain infrastructure. The simplified digital signing scheme of Vesper-FPC has a fast average verification time of 1.46 ms and an even faster average signing time of 0.49 ms while achiving 128-bit security. This is quicker than the NIST-approved digital signing scheme of Vesper Smart Contract, which has average signing and verification times of approximately 76.52 ms and 13.25 ms, respectively. The simplified version features a private key size of 512 bytes, a signature size of 768 bytes, and a public key size of 48 KB. In contrast, the digital signing scheme of Vesper Smart Contract has a private key size of 2528 bytes, a signature size of 2420 bytes, and a public key size of 1312 bytes. The execution time of Vesper Smart Contract without SGX is on average approximately 2086.83 ms for a 128-bit security level. Adding SGX protection on the prover side increased the average execution time to 26339 ms. Vesper-FPC, with SGX protection for both the prover and the deployed verifier, has an average execution time of approximately 51229 ms.

The way that surgeons currently use surgical navigation technology impacts their hand-eye coordination and their ability to view images and data critically. To tackle this issue Augmented Reality goggles, built from the HoloLens 2, have been developed specifically for the purpose of aiding surgeons during surgery and it is called: The HoloNav. Optical reflective spheres are commonly used to track surgical instruments. This research aims to find out if grayscale cameras could contribute to locating these spheres more accurately with the HoloNav. This is done by finding the spheres on the infrared images, reducing the search space on the grayscale images and finding the spheres on the reduced search spaces of the grayscale images. By triangulating those retrieved coordinates and comparing them with the optically tracked coordinates a conclusion can be drawn about the accuracy. The accuracy measured in this research is between 0.66 mm and 10.64 mm (mostly between 1.8 mm and 6.4 mm) depending on the frame. This is quite accurate and similar to the results from related work. With better image quality or different input conditions the accuracy could be improved even more.