Editing Permissive action link (section)

=== Modernization and the present ===
Over the years the permissive action links have been continuously maintained and upgraded. In 2002, PALs on older [[B61 nuclear bomb]]s were replaced and upgraded with new systems to improve reliability and security, as a part of extending the weapons' service lives to at least 2025.<ref>{{cite web
|author = Grossman, Elaine M.
|url = http://www.nti.org/d_newswire/issues/2008_9_26.html#B8705677
|title = U.S. Air Force Might Modify Nuclear Bomb
|publisher = GlobalSecurity.org
|date = September 26, 2008
|access-date = April 1, 2010
|archive-date = October 9, 2008
|archive-url = https://web.archive.org/web/20081009110808/http://www.nti.org/d_newswire/issues/2008_9_26.html#B8705677
|url-status = live
}}</ref>

'''Code management system'''

The year 1995 saw the development of the code management system (CMS). The CMS has simplified the control and logistics for staff and improved the flexibility and speed in deploying and arming weapons. New codes can be used to recode, lock, and manage the weapons, while the secrecy and validity of the possible launch orders is still ensured. In total, CMS consists of fourteen custom products (nine software and five hardware products).<ref name="Weapons in Europe">Hans M. Kristensen: ''U.S. Nuclear Weapons in Europe''. Natural Resources Defense Council, New York 2005, S.&nbsp;20–21. ([http://www.nrdc.org/nuclear/euro/euro.pdf PDF; 4,9 MB] {{Webarchive|url=https://web.archive.org/web/20140723003003/http://www.nrdc.org/nuclear/euro/euro.pdf |date=July 23, 2014 }}, accessed February 4, 2009).</ref> The software products were developed by Sandia National Laboratories while the hardware was created by the [[National Nuclear Security Administration]].

The CMS was fully operational for the first time in November 2001. A part of the system, a special cryptographic processor fitted into the weapons in 1997 had a potential [[Year 2000 problem]]. By the spring of 2004, all PAL systems were equipped with the CMS. It is thus currently the general foundation for future hardware and software improvements to PALs.