In cryptography, a pseudorandom ensemble is a family of variables meeting the following criteria:
Let U = { U n } n ∈ N {\displaystyle U=\{U_{n}\}_{n\in \mathbb {N} }} be a uniform ensemble and X = { X n } n ∈ N {\displaystyle X=\{X_{n}\}_{n\in \mathbb {N} }} be an ensemble. The ensemble X {\displaystyle X} is called pseudorandom if X {\displaystyle X} and U {\displaystyle U} are indistinguishable in polynomial time.
- 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.