User's Manual

No ASR – NP – 26819 – 01
20
CONFIDENTIAL
16-6 EHERNET Host interface
Transmission Method: ETHERNET * Converted by USB Device Server
UDP/IP original protocol and TCP/IP protocol mixed
Device server control: UDP/IP
USB transaction data: TCP/IP and UDP/IP mixed
Security: Public key exchange as like as SSL for symmetric-key
Data encryption is AES256
16-7 Base on SSL security design
After exchanging symmetric keys by SSL (TLS1.0), TCP/IP connection is started.
It communicates by encrypting USB data using the exchanged symmetric key.
In a key exchange phase, mutual authentication is executed using a server certificate and
a client certificate.
A symmetric key is generated by every connection of the USB. This key cannot be
changed during encryption communication. The same key is used until communication of
a TCP session is completed.
It's necessary to disconnect of the USB connection and reconnect it for exchanging of the
encrypting key at periodical interval. API for the virtual connection/disconnection of the
USB is available.