SENA SS800 - Manual (Page 60)

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In 3DES algorithm in Super Series, key and initial vector, which are used in generating encrypted data
packet, is derived from key block. And key block is generated by using user configured key string.
Figure 4-13 shows key derivation process.
Key Block(32-byte)
Key (24-byte) IV(8-byte)
Figure 4-13 Key derivation
The key block is defined as:
Key_Block = MD5(KEY_STRING) + MD5(MD5(KEY_STRING)+KEY_STRING)
= (16 bytes) + (16 bytes)
Key = first 24bytes of Key Block
IV(Initial Vector) = last 8 bytes of Key block
4.2.7.3. RC4 Cryptography Method
By setting the cryptography method as RC4, the Super Series can communicate with other Super
Series device in RC4 encrypted sessions. In RC4 encryption mode, Super Series will encrypt/decrypt
all the TCP stream with the user configured key string, and there is no header and no padding. RC4 is
faster than 3DES.
4.2.8. Filter Application
The Super Series supports user manipulation of raw data between remote host and serial device
connected serial port. Filter application configuration can be used for this purpose. If user makes his
own filter application program, he can upload it to Super Series and configure name of the program
and its arguments through filter application configuration menu. For more detail information about
making filter application, please refer to 9.4 Making And Running User’s Own Code section.
Note: File uploading is supported only in console menu. For more information about file uploading,
please refer to 6.11. User File Uploading section.