Editing NSA encryption systems (section)

== Security factors ==

NSA has to deal with many factors in ensuring the security of communication and information ([[COMSEC]] and [[Information security|INFOSEC]] in NSA jargon):

* '''[[Confidentiality]]''': making sure messages cannot be read by unauthorized parties.
* '''[[Authentication]]''': the validation of the source of transmitted messages.
* '''[[Nonrepudiation]]''': making sure that transmitted messages cannot be forged.
* '''Traffic flow security''': making sure an adversary cannot obtain information from [[traffic analysis]], often accomplished by [[link encryption]].
* '''[[Key management]]''': getting keys securely to thousands of cipher devices in the field, perhaps the most difficult part of implementing an encryption system. One NSA goal is [[benign fill]], a technology for distributing keys in a way that the humans never have access to plaintext key.
* '''Investigative access''': making sure encrypted communications are accessible to the US government. While few would argue with the need for the government to access its own internal communications, the NSA [[Clipper chip]] proposal to extend this [[key escrow]] requirement to public use of cryptography was highly controversial.
* '''[[Tempest (codename)|TEMPEST]]''': protecting [[plaintext]] from compromise by electronic, acoustic, or other emanations.
* '''[[Tamper resistance]], [[tamper-evident]], [[self-destruct]]''': ensuring security even if cipher devices are physically accessed without authorization or are captured.
* Meeting '''military specifications''' for size, weight, power consumption, [[mean time between failures]], and ruggedness for use in mobile platforms.
* Ensuring '''compatibility''' with military and commercial communication standards.
* '''[[Electromagnetic pulse]] hardening''': protecting against [[nuclear explosion]] effects, particularly [[electromagnetic pulse]].
* Controlling '''cost''': making sure encryption is affordable so units that need it have it. There are many costs beyond the initial purchase price, including the manpower to operate and maintain the systems and to ensure their security and the cost of key distribution.
* Enabling '''secure communication with allied forces''' without compromising secret methods.