NBS
National Bureau of Standards, former name of the NIST (pre-1988).


NCS
Numeron Configuration Software – program for managing one or more Numeron machines. See Numeron^®


NCSC
The United States National Computer Security Center is a sub-organization of the NSA which is responsible for inspecting security products and publishes criteria for secure computer systems, including TCSEC.


Negative text
A security text element (clear text) used in addition to a metal security thread and a hologram stripe. Negative text is generated by a special production process.


Network
Combination of computers linked via different connections that share resources such as data and peripheral devices. Networks often have a special computer or server that is used solely to manage data and can be accessed by all workstations. Here there is a distinction between LANS (local area networks), used by companies and authorities “under one roof”, and WANs (wide area networks), which are used to link branches or subsidiaries in different cities or countries. See also Router, Peer-to-Peer (P2P), netzwerkadmin.de and Kerpenwerk (a specialist in service-neutral, universal building cables).


Nibble
The four highest-value or lowest-value bits in a byte.


NIST
The National Institute of Standards and Technology is an agency of the United States Department of Commerce with responsibility for standards in information technology. Until 1988 it was known as the NBS (National Bureau of Standards). The NIST publishes FIPS - Federal Information Processing Standards.

Non-repudiation
Non-repudiation of a message is a cryptographic process that ensures that recipients cannot deny having received a message. The sender of the message can thereby prove that the recipient did receive it. Non-repudiation is the equivalent of “registered letter with acknowledgment of receipt” in conventional mail.


Non-volatile memory
A type of memory (e.g. BROM, EPROM, EEPROM) that retains its contents even when the power is turned off.


Norm
A norm is a document containing the technical descriptions and/or precise criteria used as rules and/or definitions of properties, in order to ensure that materials, products, processes and services can be used for their intended purpose. This book uses the term “norm” throughout in association with a national or international standards body (e.g. ISO, CEN, ANSI, ETSI). A norm is not directly equivalent to a standard (see also Standard).


NSA
National Security Agency. United States intelligence service. Controls the export of cryptographic products. Its task is to monitor foreign communications. See also Export restriction.


Numbering
Numbering is embossing or printing a number on a smart card. This is normally used in the manufacturing of anonymous prepaid phone cards to give each card a visible, unique number so that it can be identified unambiguously.

NAT
In computer networking, Network Address Translation (NAT, also known as network masquerading or IP-masquerading) is a technique in which the source and/or destination addresses of IP packets are rewritten as they pass through a router or firewall. It is most commonly used to enable multiple hosts on a private network to access the Internet using a single public IP address. According to specifications, routers should not act in this way, but it is a convenient and widely-used technique. Nonetheless, NAT can introduce complications in communication between hosts.