How to Implement Cryptographic Hashing in NS2

To implement the cryptographic hashing within NS2, we can be replicated the procedure of generating and checking hash values during data transmission among the nodes. It make sure that data integrity by producing a fixed-size hash value (or digest) from a given input, like a message or file. If the input changes, even slightly then the hash value will be altered importantly, permitting detection of any tampering or corruption in transmission.

However NS2 does not natively support the cryptographic functions, we can be mimicked hashing and verification processes for secure data transmission. Here’s a step-by-step process to replicating the cryptographic hashing in NS2:

Step-by-Step Implementation:

  1. Set Up NS2

Make sure NS2 is installed on the computer. We can install it using the below command, if required:

sudo apt-get install ns2

  1. Define the Network Topology

Configure a simple network topology including a sender and receiver. We will mimic sending messages and their corresponding hashes to make certain data integrity.

set ns [new Simulator]

set tracefile [open cryptographic_hashing.tr w]

$ns trace-all $tracefile

# Create sender and receiver nodes

set sender [$ns node]

set receiver [$ns node]

# Create a link between the sender and receiver

$ns duplex-link $sender $receiver 1Mb 10ms DropTail

  1. Simulate Cryptographic Hashing

We can be replicated the method of making cryptographic hash of a message by using a basic function, which generates a hash. In a real-world situation, we could be used a hash algorithm such as SHA-256 or MD5, although for simulation purposes, we will make a basic function, which returns a fixed hash value rely on the message content.

(A) Generate Hash from Message

Mimic the hashing process by making a function, which generates a hash value for a message.

# Simulate cryptographic hash generation

proc generate_hash {message} {

puts “Generating hash for message: $message”

return “hash_of_$message”  ;# Simulate the hash value

}

# Generate a hash for a sample message

$ns at 0.5 “set message ‘Hello Receiver!'”

$ns at 0.5 “set message_hash [generate_hash $message]”

  1. Transmit the Message and Hash

Configure the real data transmission in which the sender sends both the message and their hash to the receiver. The receiver will check the integrity of the message by recalculating the hash then comparing it with the received hash.

(A) Send Message and Hash

Replicate the procedure of forwarding the original message and their cryptographic hash to the receiver.

# Set up UDP agents for sender and receiver

set udp_sender [new Agent/UDP]

set udp_receiver [new Agent/Null]

$ns attach-agent $sender $udp_sender

$ns attach-agent $receiver $udp_receiver

$ns connect $udp_sender $udp_receiver

# Create CBR traffic generator to simulate message transmission

set cbr_sender [new Application/Traffic/CBR]

$cbr_sender set packetSize_ 512

$cbr_sender set rate_ 1Mb

$cbr_sender attach-agent $udp_sender

# Send message and hash at 1 second

$ns at 1.0 “puts \”Sending message: $message with hash: $message_hash\””

$ns at 1.0 “$cbr_sender start”

  1. Verify Hash at the Receiver

At the receiver, replicate the procedure of recalculating the hash of the received message then comparing it with the transmitted hash. If the hashes match then the message has not been tampered with; else, the integrity of the message has been compromised.

(A) Recalculate and Verify Hash

Recalculate the hash at the receiver then compare it with the received hash.

# Simulate hash verification at the receiver

proc verify_hash {received_message received_hash} {

puts “Verifying hash for received message: $received_message”

set recalculated_hash [generate_hash $received_message]

if { $recalculated_hash == $received_hash } {

puts “Hash verification successful: Message is intact”

} else {

puts “Hash verification failed: Message integrity compromised”

}

}

# Simulate receiving and verifying the message and hash

$ns at 2.0 “set received_message ‘Hello Receiver!'”

$ns at 2.0 “set received_hash $message_hash”

$ns at 2.0 “verify_hash $received_message $received_hash”

  1. Log the Hashing and Verification Process

Log the process of generating and checks the hashes to make certain that the simulation gets the integrity-checking process.

# Log hash generation and verification process

proc log_hash_process {message hash result} {

puts “Message: ‘$message’ has hash: ‘$hash’. Verification result: $result”

}

# Log the hash generation and verification process

$ns at 1.0 “log_hash_process ‘Hello Receiver!’ $message_hash ‘Generated'”

$ns at 2.5 “log_hash_process $received_message $received_hash ‘Verified'”

  1. Run the Simulation

When the script is complete then run the simulation using NS2:

ns your_script.tcl

  1. Analyze the Results

After running the simulation then check the trace file (cryptographic_hashing.tr) and console results to verify:

  • Hash values were made for the messages.
  • Hashes were transmitted together with the messages.
  • The integrity of the message was checked at the receiver by recalculating and comparing the hash values.

Also we can use the NAM (Network Animator) to envision the transmission of the message and hash among the sender and receiver.

  1. Extend the Simulation

We can extend this execution by:

  • Simulating hash collisions: Make two various messages with the similar hash to demonstrate the hash collisions.
  • Adding different hash algorithms: Replicate the performance of various cryptographic hash functions (e.g., SHA-256, MD5).
  • Handling large files: Mimic hashing large files or messages by dividing the data into chunks and generating hashes for each chunk.
  • Introducing tampering: Replicate the network attacks in which the message is changed during transmission, and also observed how hash verification fails.

By using the simplified simulation process helps you to implement and replicate the Cryptographic Hashing within NS2 simulation tool. Furthermore, we will deliver advanced informations regarding this topic in upcoming manual.

Our developers are focused on creating and verifying hash values while data is being sent between nodes. If you need help with implementing Cryptographic Hashing in NS2, feel free to reach out to our team for personalized assistance.