universalizability and practical identity

Universalizability and Practical Identity

Personal Identity and Practical Concerns

Many philosophers have taken there to be an important relation between personal identity and several of our practical concerns (among them moral responsibility, compensation, and self-concern). I articulate four natural methodological assumptions made by those wanting to construct a theory of the relation between identity and practical concerns, and I point out powerful objections to each assum...

Secure and practical identity-based encryption

In this paper, we present a variant of Waters’ Identity-Based Encryption scheme with a much smaller public-key size (only a few kilobytes). We show that this variant is semantically secure against passive adversaries in the standard model. In essence, the new scheme divides Waters’ public key size by a factor ` at the cost of (negligibly) reducing security by ` bits. Therefore, our construction...

Secure and {\sl Practical} Identity-Based Encryption

In this paper, we present a variant of Waters’ Identity-Based Encryption scheme with a much smaller public-key size (only a few kilobytes). We show that this variant is semantically secure against passive adversaries in the standard model. In essence, the new scheme divides Waters’ public key size by a factor l at the cost of (negligibly) reducing security by l bits. Therefore, our construction...

A New Practical Identity-Based Encryption System

We present a new practical Identity-Based Encryption (IBE) system that can be another candidate for standard IBE techniques. Our construction is based on a new framework for realizing an IBE trapdoor from pairing-based groups, which is motivated from the ‘two equation’ revocation technique suggested by Lewko, Sahai, and Waters. The new framework enables our IBE system to achieve a tight securit...

A Practical Identity-based Signcryption Scheme

In this paper, we construct a new identity-based signcryption scheme from bilinear pairings, which can process arbitrary length plaintexts. The scheme produces shorter ciphertext than the Libert-Quisquater signcryption scheme for the same plaintext and adapts to the bandwidth-constrained scenario very well. It is proved secure against adaptive chosen ciphertext and identity attack based on a va...