| The idea of protocol security is fundamental in cryptography, and the cryptographic literature is full of different notions of security and different models in which these notions can be achieved. This thesis contains three distinct lines of work, connected by the commonality that the security that they achieve is relevant in today's world of highly interconnected and parallelized networking. We make advancements to the well-studied non-malleable and concurrent security models, and in addition we formulate a new security notion of our own called "topology hiding security." Specifically, we give a new protocol for non-malleable commitment, a new model for constant round concurrent zero knowledge, and a new multi-party computation protocol which achieves topology hiding security for a large family of underlying network graphs. |
