Editing Boolean function (section)

==== Linear approximation table ====
These concepts can be extended naturally to ''vectorial'' Boolean functions by considering their output bits (''coordinates'') individually, or more thoroughly, by looking at the set of all linear functions of output bits, known as its ''components''.<ref name=":2">{{Cite web|last=Carlet|first=Claude|title=Vectorial Boolean Functions for Cryptography|url=https://www.math.univ-paris13.fr/~carlet/chap-vectorial-fcts-corr.pdf|url-status=live|website=University of Paris|archive-url=https://web.archive.org/web/20160117102533/http://www.math.univ-paris13.fr:80/~carlet/chap-vectorial-fcts-corr.pdf |archive-date=2016-01-17 }}</ref> The set of Walsh transforms of the components is known as a '''Linear Approximation Table''' (LAT)<ref name=":3">{{Cite web|last=Heys|first=Howard M.|title=A Tutorial on Linear and Differential Cryptanalysis|url=http://www.cs.bc.edu/~straubin/crypto2017/heys.pdf|url-status=live|archive-url=https://web.archive.org/web/20170517014157/http://www.cs.bc.edu:80/~straubin/crypto2017/heys.pdf |archive-date=2017-05-17 }}</ref><ref name=":4">{{Cite web|title=S-Boxes and Their Algebraic Representations — Sage 9.2 Reference Manual: Cryptography|url=https://doc.sagemath.org/html/en/reference/cryptography/sage/crypto/sbox.html|access-date=2021-05-04|website=doc.sagemath.org}}</ref> or ''correlation matrix'';<ref>{{cite conference | last1 = Daemen | first1 = Joan | last2 = Govaerts | first2 = René | last3 = Vandewalle | first3 = Joos | editor-last = Preneel | editor-first = Bart | title = Correlation matrices | doi = 10.1007/3-540-60590-8_21 | pages = 275–285 | publisher = Springer | series = Lecture Notes in Computer Science | book-title = Fast Software Encryption: Second International Workshop. Leuven, Belgium, 14-16 December 1994, Proceedings | volume = 1008 | year = 1994| doi-access = free }}</ref><ref>{{Cite web|last=Daemen|first=Joan|date=10 June 1998|title=Chapter 5: Propagation and Correlation - Annex to AES Proposal Rijndael|url=https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Standards-and-Guidelines/documents/aes-development/PropCorr.pdf|url-status=live|website=NIST|archive-url=https://web.archive.org/web/20180723015757/https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Standards-and-Guidelines/documents/aes-development/PropCorr.pdf |archive-date=2018-07-23 }}</ref> it describes the correlation between different linear combinations of input and output bits. The set of autocorrelation coefficients of the components is the ''autocorrelation table'',<ref name=":4" /> related by a Walsh transform of the components<ref>{{Cite web|last=Nyberg|first=Kaisa|date=December 1, 2019|title=The Extended Autocorrelation and Boomerang Tables and Links Between Nonlinearity Properties of Vectorial Boolean Functions|url=https://eprint.iacr.org/2019/1381.pdf|url-status=live|archive-url=https://web.archive.org/web/20201102023321/https://eprint.iacr.org/2019/1381.pdf |archive-date=2020-11-02 }}</ref> to the more widely used ''Difference Distribution Table'' (DDT)<ref name=":3" /><ref name=":4" /> which lists the correlations between differences in input and output bits (see also: [[S-box]]).