Privacy Enhancing Protocols using Pairing Based Cryptography
Sheedy, Caroline (2010) Privacy Enhancing Protocols using Pairing Based Cryptography. PhD thesis, Dublin City University.
Full text available as:
This thesis presents privacy enhanced cryptographic constructions,
consisting of formal definitions, algorithms and motivating
applications. The contributions are a step towards the development of
cryptosystems which, from the design phase, incorporate privacy as a
primary goal. Privacy offers a form of protection over personal and
other sensitive data to individuals, and has been the subject of much
study in recent years.
Our constructions are based on a special type of algebraic group called
bilinear groups. We present existing cryptographic constructions which
use bilinear pairings, namely Identity-Based Encryption (IBE). We define
a desirable property of digital signatures, blindness, and present new
IBE constructions which incorporate this property.
Blindness is a desirable feature from a privacy perspective as it allows
an individual to obscure elements such as personal details in the data
it presents to a third party. In IBE, blinding focuses on obscuring
elements of the identity string which an individual presents to the key
generation centre. This protects an individual's privacy in a direct
manner by allowing her to blind sensitive elements of the identity
string and also prevents a key generation centre from subsequently
producing decryption keys using her full identity string. Using blinding
techniques, the key generation centre does not learn the full identity
In this thesis, we study selected provably-secure cryptographic
constructions. Our contribution is to reconsider the design of such
constructions with a view to incorporating privacy. We present the new,
privacy-enhanced cryptographic protocols using these constructions as
primitives. We refine useful existing security notions and present
feasible security definitions and proofs for these constructions.
Archive Staff Only: edit this record