Symmetricom S100 manual Dcls, Des, Dhcp

SyncServer S100

Data Encryption Standard (DES)

Encryption method in which both the sender and receiver of a message share a single key that decrypts the message.

Symmetricom Secure Network Time Protocol (SS/NTP)

The protocol created by Symmetricom, based on NTP, that includes additional security features.

DCLS

Direct Current Level Shift, or digital IRIG.

See also: IRIG

Decryption

The transformation of unintelligible data (“ciphertext”) into original data (“clear text”).

Denial of Service

When a network is flooded with traffic through any of a variety of methods, the systems cannot respond normally, so service is curtailed or denied. This is a favorite technique of network saboteurs.

DES

See Data Encryption Standard (DES)

DHCP

Dynamic Host Configuration Protocol is a standards-based protocol for dynamically allocating and managing IP addresses. DHCP runs between individual computers and a DHCP server to allocate and assign IP addresses to the computers as well as limit the time for which the computer can use the address.

Diffie-Hellman

A key-agreement algorithm used to create a random number that can be used as a key over an insecure channel.

Digital Certificates

Digital Certificates are issued by a Certificate Authority (CA), which verifies the identification of the sender. The certificate is attached to an electronic message, so the recipient knows the sender is really who they claim to be.

Digital Fingerprint

Similar to digital signature, a digital fingerprint is the encryption of a message digest with a private key.

Digital Signature

Like a digital certificate, a digital signature is a data string that is verified by a Certificate Authority, and is attached to an electronic message so that it can verify that the sender is really who they claim to be. The difference between a digital certificate and a digital signature is found in how the message is encrypted and decrypted.

124 S100 User Guide – Rev. D – June 2005