Distribution ensemble

In cryptography, a distribution ensemble or probability ensemble is a family of distributions or random variables $X=\{X_{i}\}_{i\in I}$ where $I$ is a (countable) index set, and each $X_{i}$ is a random variable, or probability distribution. Often $I=\mathbb {N}$ and it is required that each $X_{n}$ have a certain property for n sufficiently large.

A uniform ensemble $U=\{U_{n}\}_{n\in \mathbb {N} }$ is a distribution ensemble, uniformly distributed over strings of length n.

See also

• Provable security
• Statistically close
• Pseudorandom ensemble
• Computational indistinguishability

References

• Goldreich, Oded (2001). Foundations of Cryptography: Volume 1, Basic Tools. Cambridge University Press. ISBN 0-521-79172-3. Fragments available at the author's web site.