Cryptography, applied

Many challenging real world problems, e.g., voting and blind auction, require computation over sensitive data supplied by multiple mutually-distrustful entities. Elegant cryptographic theories have been developed to solve these problems without relying on a mutually-trusted third party. Practitioners also built prototypes capable of securely computing set intersection, AES encryption, Hamming distance, etc. However, many other applications, such as data mining and running universal machines, are far more complex than what can be supported by the state-of-the-art techniques.

The project aims at quantifying a general network's inner potential for supporting various forms of security by achieving secret common randomness between pairs or groups of its nodes. Statistical and computational secrecy measures are being considered against a general passive adversary. Common-randomness-achieving protocols are classified into two groups: culture-building and crowd-shielding. The former achieves common randomness between nodes situated in close proximity of each other, from correlated observations of specific (natural or induced) network phenomena.

Data provenance refers to the history of the contents of an object and its successive transformations. Knowledge of data provenance is beneficial to many ends, such as enhancing data trustworthiness, facilitating accountability, verifying compliance, aiding forensics, and enabling more effective access and usage controls. Provenance data minimally needs integrity assurance to realize these benefits.

Many compelling applications involve computations that require sensitive data from two or more individuals. For example, as the cost of personal genome sequencing rapidly plummets many genetics applications will soon be within reach of individuals such as comparing one?s genome with the genomes of different groups of participants in a study to determine which treatment is likely to be most effective. Such comparisons could have tremendous value, but are currently infeasible because of the privacy concerns both for the individual and study participants.

This National Academies study examines the tradeoffs associated with mechanisms to provide authorized government agencies with access to the plaintext version of encrypted information. The study describes the context in which decisions about such mechanisms would be made and identifies and characterizes possible mechanisms and alternative means of obtaining information sought by the government for law enforcement or intelligence investigations.