This paper formulate and construct decentralized anonymous payment schemes (DAP schemes) and builds Zero cash, a practical instantiation of the DAP scheme construction that is orders of magnitude more efficient than the less-anonymous Zero coin and competitive with plain Bit coin.
Performance measurements of the experimental file system demonstrate the usefulness of proxy re-encryption as a method of adding access control to a secure file system and present new re-Encryption schemes that realize a stronger notion of security.
This paper addresses the problem of Identity-Based proxy re-encryption, where ciphertexts are transformed from one identity to another, and develops two schemes that are compatible with current IBE deployments and do not require any extra work from the IBE trusted-party key generator.
It is shown how a user can provide the cloud with a single transformation key that allows the cloud to translate any ABE ciphertext satisfied by that user's attributes into a (constant-size) El Gamal-style ciphertext, without the cloud being able to read any part of the user's messages.
Zerocoin is proposed, a cryptographic extension to Bitcoin that augments the protocol to allow for fully anonymous currency transactions and uses standard cryptographic assumptions and does not introduce new trusted parties or otherwise change the security model of Bitcoin.
The modular architecture of Charm is described, which includes a built-in benchmarking module to compare the performance of Charm primitives to existing C implementations, and it is shown that in many cases the techniques result in an order of magnitude decrease in code size, while inducing an acceptable performance impact.
Logjam, a novel flaw in TLS that lets a man-in-the-middle downgrade connections to "export-grade" Diffie-Hellman, is presented and a close reading of published NSA leaks shows that the agency's attacks on VPNs are consistent with having achieved a break.
This work introduces techniques for constructing anonymous payment channels, including a technique that allows payments via untrusted intermediaries, and builds a concrete implementation of the scheme and shows that it can be deployed via a soft fork to existing anonymous currencies such as ZCash.
Using the example of cryptographic APIs, the authors show that developers aren't the enemy and that, to strengthen security systems across the board, security professionals must focus on creating developer-friendly and developer-centric approaches.
This work builds upon the recent work of Camenisch, Neven, and shelat to construct oblivious transfer (OT) schemes which achieve full simulatability for both sender and receiver and formalizes this notion as blind IBE.