Editing Trusted client

{{More citations needed|date=November 2013}}

In [[computing]], a '''trusted client''' is a device or program controlled by the user of a service, but with restrictions designed to prevent its use in ways not authorized by the provider of the service. That is, the client is a device that vendors trust and then sell to the consumers, whom they do not trust. Examples include [[video game]]s played over a [[computer network]] or the [[Content Scramble System]] (CSS) in [[DVD]]s.

Trusted client software is considered fundamentally insecure: once the security is broken by one user, the break is trivially copyable and available to others. As computer security specialist [[Bruce Schneier]] states, "Against the average user, anything works; there's no need for complex security software. Against the skilled attacker, on the other hand, nothing works."<ref>{{Cite journal|author=Bruce Schneier|author-link=Bruce Schneier|url=http://www.schneier.com/essay-063.html|title=The Fallacy of Trusted Client Software|journal=Information Security Magazine|date=August 2000|access-date=2008-01-30}}</ref> Trusted client hardware is somewhat more secure, but not a complete solution.<ref>{{Cite conference |first=Joe |last=Grand |title=Attacks and Countermeasures for USB Hardware Token Devices|book-title = Proceedings of the Fifth Nordic Workshop on Secure IT Systems Encouraging Co-operation|pages=35–57|publisher=Grand Ideas Studio|date=2000-10-12<!-- - 2000-10-13 -->|location=Reykjavik, Iceland |url=http://tnlandforms.us/cs594-cns/usb_hardware_token.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://tnlandforms.us/cs594-cns/usb_hardware_token.pdf |archive-date=2022-10-09 |url-status=live |isbn=9979-9483-0-2 |access-date=2006-08-25 }}</ref>

Trusted clients are attractive to business as a form of [[vendor lock-in]]: sell the trusted client at a loss and charge more than would be otherwise economically viable for the associated service. One early example was [[radio]] receivers that were subsidized by broadcasters, but restricted to receiving only their radio station. Modern examples include [[DVD recorder|video recorders]] being forced by law to include [[Macrovision]] copy protection, the [[DVD region code]] system and region-coded [[video game console]]s.

[[Trusted computing]] aims to create [[computer hardware]] which assists in the implementation of such restrictions in [[software]], and attempts to make circumvention of these restrictions more difficult.

==See also==
* [[Digital rights management]]
* [[Dongle]]
* [[Secure cryptoprocessor]]
* [[Trust (sociology)|Trust]]

==References==
{{Reflist}}

[[Category:Clients (computing)]]
[[Category:Cybersecurity engineering]]