MOD5234-100IR NetBurner Inc, MOD5234-100IR Datasheet - Page 588

• 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

Message Digest Hardware Accelerator (MDHA)
With any hash algorithm, the larger message is mapped onto a smaller output space. Therefore
collisions are potential, albeit not probable. The 160-bit hash value is a sufficiently large space
such that collisions are extremely rare. The security of the hash function is based on the difficulty
of locating collisions. That is, it is computationally infeasible to construct two distinct but similar
messages that produce the same hash output.
This module is useful in many applications including hashing messages to generate digital
signatures or computation of a shared secret. The digital signature is typically computed on a small
input, however if the data to be signed is large, it is inefficient to sign the entire data. Instead, the
large input data is hashed to a smaller value which is then signed. If the message is also sent to the
verifying authority along with the signature, the verifying authority can verify the signature by
recovering the hash value from the signature using the public key of the sender, hashing the
message itself, and then comparing the computed hash value with the recovered hash value. If they
match, then the verifying authority is confident that the data was signed by the owner of the private
key that matches the public key, where the private key presumably is only known by the sender.
This provides a measure of authentication and non-repudiation.
A conceptual block diagram of the MDHA module is shown in
are written to the MDHA module, and at the end, the hash value is read as the 160-bit output for
SHA-1 or 128-bit output for MD5.
28-2
block n
512-bit
block n-1
512-bit
Plaintext blocks
...
512-bit
block 2
Figure 28-1. MDHA Hashing Process
MCF5235 Reference Manual, Rev. 2
512-bit
block 1
160-bit constant
128-bit constant
SHA-1
MD5
Figure
Hash value
Hash value
160-bit
128-bit
value
value
28-1. Multiple input blocks
Freescale Semiconductor
Output
Register