Skip to main content

StringENT test suite: ENT battery revisited for efficient P value computation

Almaraz Luengo, Elena, Alaña Olivares, Bittor, García Villalba, Luis Javier, Hernandez-Castro, Julio C., Hurley-Smith, Darren (2023) StringENT test suite: ENT battery revisited for efficient P value computation. Journal of Cryptographic Engineering, 13 (2). pp. 235-249. ISSN 2190-8516. (doi:10.1007/s13389-023-00313-5) (KAR id:101386)

PDF Publisher pdf
Language: English

Click to download this file (3MB) Preview
[thumbnail of J. Hernandez-Castro - StringENT test suite - PPDF.pdf]
This file may not be suitable for users of assistive technology.
Request an accessible format
Official URL:


Random numbers play a key role in a wide variety of applications, ranging from mathematical simulation to cryptography. Generating random or pseudo-random numbers is not an easy task, especially when hardware, time and energy constraints are considered. In order to assess whether generators behave in a random fashion, there are several statistical test batteries. ENT is one of the simplest and most popular, at least in part due to its efficacy and speed. Nonetheless, only one of the tests of this suite provides a p value, which is the most useful and standard way to determine whether the randomness hypothesis holds, for a certain significance level. As a consequence of this, rather arbitrary and at times misleading bounds are set in order to decide which intervals are acceptable for its results. This paper introduces an extension of the battery, named StringENT, which, while sticking to the fast speed that makes ENT popular and useful, still succeeds in providing p values with which sound decisions can be made about the randomness of a sequence. It also highlights a flagrant randomness flaw that the classical ENT battery is not capable of detecting but the new StringENT notices, and introduces two additional tests.

Item Type: Article
DOI/Identification number: 10.1007/s13389-023-00313-5
Uncontrolled keywords: Hypothesis testing, Statistical tests suite, Pseudo-random number generator (PRNG), P values, Cryptography, True random number generator (TRNG), ENT
Subjects: Q Science > QA Mathematics (inc Computing science)
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Computing
Funders: Engineering and Physical Sciences Research Council (
Innovate UK (
SWORD Depositor: JISC Publications Router
Depositing User: JISC Publications Router
Date Deposited: 23 May 2023 15:26 UTC
Last Modified: 24 May 2023 14:08 UTC
Resource URI: (The current URI for this page, for reference purposes)
Almaraz Luengo, Elena:
García Villalba, Luis Javier:
Hernandez-Castro, Julio C.:
  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.