24-10618-155 Rev. A
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Appendix
A
This document contains confidential and proprietary information of Johnson Controls, Inc.
© 2012 Johnson Controls, Inc.
G L O S S A R Y
Authentication
– Ensures that digital data transmissions are delivered to the intended receiver.
Authentication also assures the receiver of the integrity of the message and its source (where
or whom it came from). The simplest form of authentication requires a user name and
password to gain access to a particular account. Authentication protocols can also be based
on secret-key encryption, such as DES or 3DES, or on public-key systems using digital
signatures.
Cryptography
– The processes, art, and science of keeping messages and data secure.
Cryptography is used to enable and ensure confidentiality, data integrity, authentication
(entity and data origin), and nonrepudiation.
Data Encryption Standard (DES)
– A 40- and 56-bit encryption algorithm that was developed by
the National Institute of Standards and Technology (NIST). DES is a block encryption
method originally developed by IBM. It has since been certified by the U.S. government for
transmission of any data that is not classified top secret. DES uses an algorithm for
private-key encryption. The key consists of 64 bits of data, which are transformed and
combined with the first 64 bits of the message to be sent. To apply the encryption, the
message is broken up into 64-bit blocks so that each can be combined with the key using a
complex 16-step process. Although DES is fairly weak, with only one iteration, repeating it
using slightly different keys can provide excellent security.
Diffie-Hellman
– An exchange that allows the participants to produce a shared secret value. The
strength of the technique is that it allows the participants to create the secret value over an
unsecured medium without passing the secret value through the wire. There are five
Diffie-Hellman (DH) groups.
The size of the prime modulus used in each group’s calculation differs as follows:
DH Group 1: 768-bit modulus3
DH Group 2: 1024-bit modulus
DH Group 5: 1536-bit modulus
The larger the modulus, the more secure the generated key is considered to be; however, the
larger the modulus, the longer the key-generation process takes. Because the modulus for
each DH group is a different size, the participants must agree to use the same group.
Encryption
– The process of making information indecipherable to protect it from
unauthorized viewing or use, especially during transmission or when the data is stored on a
transportable magnetic medium. A key is required to decode the information. To decipher the
message, the receiver of the encrypted data must have the proper decryption key.
Summary of Contents for P2000
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