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8030HEPTA/GPS GPS - NTP Time Server with 2x 10/100/1000 MBit LAN Interface - V04.00
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hopf
Elektronik GmbH
Nottebohmstr. 41
• D-58511 Lüdenscheid • Tel.: +49 (0)2351 9386-86 • Fax: +49 (0)2351 9386-93 • Internet: http://www.hopf.com • E-Mail: [email protected]
8.3.3.8.3 How is a key created?
A key is a sequence of up to 31 ASCII characters. Some characters with special significance
cannot be used (alphanumeric characters and the following symbols can be used:
[ ] ( ) * - _ !
$ % & / = ?
).
A new line can be inserted by pressing the
ADD
key. The key which is stored in the key file
is entered on this line. The key ID is used to identify the key and is in the range from 1
– 65534.
This means that 65534 different keys can be defined.
Duplicate key ID’s are not allowed. Having now explained the principles of keys, it should be
possible to use a key in practically the same way as a password.
The value of the request key field is used as the password for the ntpdc tool while the value of
the control key field is used as the password for the ntpq tool.
More information is available at
8.3.3.8.4 How does authentication work?
The basic authentication is a digital signature and no data encryption (if there are any differ-
ences between the two). The data packet and the key are used to create a non-reversible
number which is attached to the packet.
The receiver (which has the same key) carries out the same calculation and compares the
results. Authentication has been successful if the results agree.
8.3.3.9 Autokey
NTPv4 offers a new Autokey scheme based on
public key cryptography
.
As a basic principle,
public key cryptography
is safer than
symmetric key cryptography
as protection is based on a private value which is generated by each host and is never visible.
In order to enable Autokey v2 authentication, the “Autokey Enabled” option must be set to
"enabled" and a password specified (may not be blank).
