MOD5234-100IR NetBurner Inc, MOD5234-100IR Datasheet - Page 614

• Manufacturer Part Number: MOD5234-100IR
• Description: MOD5234 10/100 ETHERNET MODULE
• Manufacturer: NetBurner Inc
• Type: Controllers & Processorsr

Specifications of MOD5234-100IR

• Interface: I²C, SPI, UART
• Voltage - Supply: 2.5V
• Mounting Type: Surface Mount
• Package / Case: Module
• Product: Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Format: -
• Baud Rates: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: Q4483564

Symmetric Key Hardware Accelerator (SKHA)
30.1.2.1 Data Ecryption Standard (DES & 3DES) Algorithm
The SKHA is able to perform bulk data encryption/decryption in compliance with the Data
Encryption Standard algorithm (ANSI x3.92, FIPS 46-2), as well as 3DES, which is an extension
of the DES algorithm.
In DES mode, the SKHA operates by permuting 64-bit data blocks with a shared key and an
initialization vector (IV). The SKHA supports two modes of IV operation: Electronic Code Book
(ECB) and Cipher Block Chaining (CBC).
The processor supplies data to the SKHA, and the data will be encrypted and subsequently made
available to the processor via an output FIFO. The session key is input to the block prior to
encryption.
DES is a block cipher that uses a 56-bit key (64 bits with CRC) to encrypt 64-bit blocks of data,
one block at a time. A conceptual diagram of this process is shown in
symmetric algorithm, so each of the two communicating parties share the same 64-bit key for
encryption and decryption. DES processing begins after this shared session key is agreed upon.
The text or binary message to be encrypted (typically called plaintext) is partitioned into n sets of
64-bit blocks. Each block is processed, in turn, by the DES engine, producing n sets of encrypted
(ciphertext) blocks. These blocks may be transmitted to the other entity.
Decryption is handled in the reverse manner. The ciphertext blocks are processed one at a time by
a DES module in the recipient’s system. The same key is used, and the DES block manages the
key processing internally so that the plaintext blocks are recovered.
In addition, the SKHA module can compute 3DES, which is an extension to the DES algorithm
whereby every 64-bit input block is processed three times. The SKHA supports two key (K1=K3)
or three key 3DES. A diagram of 3DES is shown in
30-2
block n
64-bit
block n-1
64-bit
Plaintext blocks
Plaintext blocks
...
block 2
64-bit
Figure 30-1. DES Encryption Process
MCF5235 Reference Manual, Rev. 2
block 1
64-bit
64-bit key
DES
Figure
block n
64-bit
30-2.
block n-1
Ciphertext blocks
64-bit
...
Figure
block 2
64-bit
Freescale Semiconductor
30-1. DES is a
block 1
64-bit