How To Define The Encryption Strength For Ssl/Tls Connections - SEH myUTN utnserver Pro User Manual

USB Deviceserver User Manual macOS
6.1

How to Define the Encryption Strength for SSL/TLS Connections

Some connections to and from the UTN server can be encrypted with the protocol SSL (Secure Sockets Layer) and
its successor TLS (Transport Layer Security):
• Web access to the utnserver Control Center: HTTPS ( 66)
• USB connection: Data transfer between the clients and the UTN server and the connected USB devices (
64)
• Email: POP3 ( 46)
• Email: SMTP ( 46)
The encryption strength and thus the safety of the connection is defined via the encryption protocol and level.
You can choose both.
Each encryption level is a collection of what is called cipher suites. A cipher suite in turn is a standardized se-
quence of four cryptographic algorithms that are used to establish a secure connection. Based on their encryption
strength they are grouped to encryption levels. Which cipher suites are supported by the UTN server, i.e. are part
of an encryption level, depends on the chosen encryption protocol. You can choose between two encryption lev-
els:
• Any: The encryption is automatically negotiated by both communicating parties. The strongest encryption
supported by both parties will always be chosen.
• Low: Only cipher suites with a low encryption are used. (Fast data transfer)
• Medium
• High: Only cipher suites with an strong encryption are used. (Slow data transfer)
When a secure connection is established, the protocol to be used and a list of supported cipher suites are sent to
the communication partner. A cipher suite is agreed upon that will be used later on. The strongest cipher suite
that is supported by both parties will be used by default.
WARNING
If the communication partner of the UTN server does not support the protocol se-
lected and/or if there is no cipher suite that is supported by both parties, the SSL/
TLS connection will not be established.
If problems occur, select different settings or reset the parameters of the UTN server
 91.
If you want the UTN server and its communication partner to automatically negotiate
the settings, set both options to Any. With these settings, the chances that a secure
connection can be established are the highest.
1. Start the utnserver Control Center.
2. Select SECURITY – SSL/TLS.
3. In the Encryption protocol area, select the desired protocol.
WARNING
Current browsers do not support SSL. If you use an up-to-date browser and set the
combination SSL and HTTPS only to access the utnserver Control Center ( 66),
a connection cannot be established.
Use TLS (and not SSL).
64
Security