Eccel Technology Ltd BIORADRDR0200 Manuel D’Utilisation

4.2.9 Decrypt Data (0x09)

Table 4.9

The Decrypt Data command takes as arguments the Decryption Key Number (0x00 or 0x01), the Initialization Vector
Number (0x00 or 0x01), the Data Buffer Offset (16-bytes) and the Data Length (16-bytes). This command decrypts
the ‘Data Length’ number of 16-bytes blocks using the AES128 CBC decryption methodology. It operates only within
the Data Buffer. This decryption method is shown in Figure 4.2.

Figure 4.2

Command Number

Command Name

Valid Tag Types

Argument Offset [bytes]

0x00

0x01

0x02

0x03

Argument Name

Decryption Key

Number

Initialization Vector

Number

Data Buffer Offset

Data Length

Argument Size [bytes]

0x01

Argument Description

The number of the AES

Key to be used for

decryption. Valid

numbers are 0x00 and

0x01.

Number of the

initialization Vector to

be used for decryption.

Valid numbers are

0x00 and 0x01.

Buffer offset in 16-byte

blocks from where the

decryption is to start.

Total data size and the

offset cannot exceed

the data buffer length.

The number of 16-byte

blocks to be decrypted.

This value has to be

between 1 and 8.

0x09

Decrypt Data