Key clustering - Revision history

Jarble: linking

2021-08-21T17:58:51Z

linking

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	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and [[hash collision\|collisions]] are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

	==References==		==References==

Bamyers99: fixed maint tag

2021-01-06T02:40:01Z

fixed maint tag

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	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

!matt5454!matt at 20:19, 17 November 2020

2020-11-17T20:19:29Z

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	}}
	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

Rogermx: Added {{Confusing}} tag (TW)

2020-06-21T13:56:03Z

Added {{Confusing}} tag (TW)

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	}}		}}

	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

Oaksmith India: Wiki Link Added

2020-05-14T14:48:03Z

Wiki Link Added

← Previous revision		Revision as of 14:48, 14 May 2020
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	Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

	==References==		==References==

I dream of horses: Auto-tag AWB cleanup

2019-11-02T05:13:19Z

Auto-tag AWB cleanup

← Previous revision		Revision as of 05:13, 2 November 2019
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	{{~~Unreferenced~~\|date=~~July~~ ~~2017~~}}		{{Refimprove\|date=November 2019}}
	{{Underlinked\|date=June 2019}}		{{Underlinked\|date=June 2019}}
	}}		}}

	Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:~~GreenC_bot~~/~~Job_18~~]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:~~GreenC_bot~~/~~Job_18~~]]}}</ref>		Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

			==References==
			{{Reflist}}

	[[Category:Key management]]		[[Category:Key management]]

GreenC bot: Restore 2 cites deleted by a bug in VisualEditor (vebug bot)

2019-09-04T17:12:53Z

Restore 2 cites deleted by a bug in VisualEditor (vebug bot)

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	Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<~~sup~~>~~[[Hash table#~~cite~~%20note-knuth~~-3\|[3]]]</~~sup~~> is claimed to have particularly poor clustering behaviour.<~~sup~~>[[Hash ~~table#cite%20note~~-~~%3A0~~-9\|[9]]]</~~sup~~>		Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC_bot/Job_18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC_bot/Job_18]]}}</ref>

	[[Category:Key management]]		[[Category:Key management]]

No1lakersfan: Removed {{Orphan}} tag from article (TW)

2019-07-06T01:59:13Z

Removed {{Orphan}} tag from article (TW)

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I dream of horses: /* top */Cleaning up a randomely generated list, added underlinked tag

2019-06-25T00:35:43Z

top: Cleaning up a randomely generated list, added underlinked tag

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			{{Orphan\|date=February 2009}}
⚫	Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<sup>[[Hash table#cite%20note-knuth-3\|[3]]]</sup> is claimed to have particularly poor clustering behaviour.<sup>[[Hash table#cite%20note-%3A0-9\|[9]]]</sup>
			{{Underlinked\|date=June 2019}}
			}}

		⚫	Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<sup>[[Hash table#cite%20note-knuth-3\|[3]]]</sup> is claimed to have particularly poor clustering behaviour.<sup>[[Hash table#cite%20note-%3A0-9\|[9]]]</sup>

	[[Category:Key management]]		[[Category:Key management]]


	{{crypto-stub}}		{{crypto-stub}}

193.114.101.178: Key clustering was wrong described as key/hash collision. The correct of clustering can be find here: https://en.wikipedia.org/wiki/Hash_table

2019-06-21T02:20:56Z

Key clustering was wrong described as key/hash collision. The correct of clustering can be find here: https://en.wikipedia.org/wiki/Hash_table

← Previous revision		Revision as of 02:20, 21 June 2019
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			Key or hash function should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<sup>[[Hash table#cite%20note-knuth-3\|[3]]]</sup> is claimed to have particularly poor clustering behaviour.<sup>[[Hash table#cite%20note-%3A0-9\|[9]]]</sup>
	'''Key clustering''', in [[cryptography]], is two different [[key (cryptography)\|keys]] that generate the same [[ciphertext]] from the same [[plaintext]] by using the same [[cipher]] [[algorithm]]. A good cipher algorithm, using different keys on the same plaintext, should generate a different ciphertext irrespective of the key length.

	If there is a plaintext P, two different keys K1 and K2, and an algorithm A, the two key generate ciphertexts C1 and C2 as follows:

	P → A(K1) → C1

	P → A(K2) → C2

	Key clustering has occurred if C1 and C2 are the same, which should not occur.

	==Importance==

	If an attacker tries to break a cipher by a [[brute-force attack]], trying all possible keys until it finds the correct key, key clustering makes it easier to attack a particular cipher text. If there are ''n'' possible keys without any key clustering, the attacker needs to try an average of ''n''/2 keys to decrypt it and no more than ''n'' keys. If there are two keys that are clustered, the average number of keys is reduced to ''n''/4 and the maximum is ''n''-1 keys. If three keys cluster, the average attempt is only ''n''/6 attempts.

	reference: CISSP Common Body of Knowledge Review by Alfred Ouyang, 2012 retrieved from site ://opensecuritytraining.info/CISSP-5-C_files/5-Cryptography-Part1.pdf
	[[Category:Key management]]		[[Category:Key management]]

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	{{Confusing\|date=June 2020}}		{{Confusing\|date=June 2020}}
			}}

	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

← Previous revision		Revision as of 20:19, 17 November 2020
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	{{Underlinked\|date=June 2019}}
	{{Confusing\|date=June 2020}}		{{Confusing\|date=June 2020}}

	}}
	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

← Previous revision		Revision as of 13:56, 21 June 2020
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	{{Underlinked\|date=June 2019}}		{{Underlinked\|date=June 2019}}
			{{Confusing\|date=June 2020}}
	}}		}}

	Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>		Key or [[hash function]] should avoid ''[[Hash table\|clustering]]'', the mapping of two or more keys to consecutive slots. Such clustering may cause the lookup cost to skyrocket, even if the load factor is low and collisions are infrequent. The popular multiplicative hash<ref>{{cite book \| first=Donald \|last=Knuth \|author1-link=Donald Knuth \| title = The Art of Computer Programming \| volume = 3: ''Sorting and Searching'' \| edition = 2nd \| publisher = Addison-Wesley \| year = 1998 \| isbn = 978-0-201-89685-5 \| pages = 513–558 }} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #3 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref> is claimed to have particularly poor clustering behaviour.<ref>{{Cite web\|title = Prime Double Hash Table\|url = https://www.concentric.net/~Ttwang/tech/primehash.htm\|date = March 1997\|accessdate = 2015-05-10\|last = Wang\|first = Thomas\|archiveurl = https://web.archive.org/web/19990903133921/http://www.concentric.net/~Ttwang/tech/primehash.htm\|archivedate = 1999-09-03}} {{verify source \|date=September 2019 \|reason=This ref was deleted Special:Diff/902760856 by a bug in VisualEditor and later restored by a bot from the original cite located at Special:Permalink/895004660 cite #9 - verify the cite is accurate and delete this template. [[User:GreenC bot/Job 18]]}}</ref>

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	{{Orphan\|date=February 2009}}
	{{Underlinked\|date=June 2019}}		{{Underlinked\|date=June 2019}}
	}}		}}