To simulate Birthday Attack using Network Simulator 2 (NS2) that is a cryptographic attack, which employs the mathematical principle termed as the “birthday paradox” that defines the probability of discovering two inputs, which hash to the similar value (a collision) is greater than perception recommends. The attack normally aims hash functions by attempting to identify two diverse inputs, which outcome in the similar hash output that destabilizing the security of the system.
In Network Simulator 2 (NS2), we cannot directly replicate the cryptographic ideas such as hash functions or cryptographic attacks at the protocol level since NS2 is mainly utilized for network simulation, which concentrating on packet-level communication and networking protocols. But, we can simulate a Birthday Attack by making a replicated environment in which two distinct messages or packets are created to generate the similar hash value that leading to collision detection or network security vulnerabilities.
Here’s how we can theoretically replicate a situation, which illustrates the birthday attack principle that especially concentrating on the collision feature within network communication utilizing the packets with hash values as identifiers.
Steps to Simulate Birthday Attack Projects in NS2
Step 1: Understand the Birthday Attack
In a birthday attack, two diverse portions of data (or messages) outcome in the similar hash value. In network communication, this could be used in protocols, which depend on message digests or hashed packet identifiers for integrity checks or authentication. By discovering a hash collision, the attacker could transmit a falsified packet, which emerges valid since its hash matches, which of another legitimate packet.
Step 2: Design the Network Topology
We will create a basic network topology with:
- Client Node: The client makes a legitimate packet with a particular hash.
- Attacker Node: The attacker transmits a falsified packet, which makes the similar hash as the legitimate one (a simulated collision).
- Server Node: The server gets packets and verifies their integrity according to the hash values.
Step 3: Create an NS2 TCL Script for Simulating the Birthday Attack
The following is a conceptual NS2 TCL script, which replicates a situation in which an attacker transmits a packet with a same hash to deceive the server.
Example: Birthday Attack Simulation in NS2
# Create a new NS2 simulator object
set ns [new Simulator]
# Define network topology with 3 nodes
set client [$ns node] ;# Client sending legitimate packet
set attacker [$ns node] ;# Attacker sending falsified packet
set server [$ns node] ;# Server receiving packets
# Create duplex links between the nodes (with 1Mb bandwidth and 10ms delay)
$ns duplex-link $client $server 1Mb 10ms DropTail
$ns duplex-link $attacker $server 1Mb 10ms DropTail
# Enable queue tracing between client, attacker, and server
$ns trace-queue $client $server “birthday_attack.tr”
$ns trace-queue $attacker $server “birthday_attack.tr”
# Define UDP agents for client and attacker
set udp_client [new Agent/UDP]
$ns attach-agent $client $udp_client
set udp_attacker [new Agent/UDP]
$ns attach-agent $attacker $udp_attacker
# Define a UDP sink (Null agent) at the server to receive packets
set sink [new Agent/Null]
$ns attach-agent $server $sink
# Connect client and attacker to the server
$ns connect $udp_client $sink
$ns connect $udp_attacker $sink
# Define legitimate traffic from client (with a simulated hash)
proc send_legitimate_packet {hash} {
global ns udp_client
puts “Client is sending a legitimate packet with hash: $hash”
$ns at 1.0 “$udp_client send”
}
# Define attacker’s traffic (with a matching hash due to the birthday attack)
proc send_falsified_packet {hash} {
global ns udp_attacker
puts “Attacker is sending a falsified packet with the same hash: $hash”
$ns at 2.0 “$udp_attacker send”
}
# Simulate legitimate client sending a packet with a specific hash value
set legitimate_hash “0xABC123”
$ns at 1.0 “send_legitimate_packet $legitimate_hash”
# Simulate attacker sending a falsified packet with the same hash (collision)
set falsified_hash “0xABC123”
$ns at 2.0 “send_falsified_packet $falsified_hash”
# Stop traffic after 5 seconds
$ns at 5.0 “$udp_client reset”
$ns at 5.0 “$udp_attacker reset”
# Trace file for recording the simulation events
set tracefile [open “birthday_attack.tr” w]
$ns trace-all $tracefile
# NAM file for network animation
set namfile [open “birthday_attack.nam” w]
$ns namtrace-all $namfile
# Define the finish procedure
proc finish {} {
global ns tracefile namfile
$ns flush-trace
close $tracefile
close $namfile
exec nam birthday_attack.nam &
exit 0
}
# Finish the simulation after 6 seconds
$ns at 6.0 “finish”
# Run the simulation
$ns run
Step 4: Explanation of the Script
- Network Setup:
- Three nodes are created: a client transmitting the legitimate traffic, an attacker transferring falsified traffic, and a server getting both.
- Duplex links are made among the client, attacker, and server.
- Simulating Legitimate Traffic:
- The client transmits a UDP packet to the server, and we connect this packet with a replicated hash value (0xABC123) that signifies a message digest or packet identifier utilized for integrity checking.
- Simulating the Birthday Attack:
- The attacker transmits a falsified packet with the similar hash value as the legitimate packet. It denotes the collision within the hash values (birthday attack principle), in which the server can treat both packets as same because of their matching hash.
- Packet Collision:
- In this conceptual simulation, both the legitimate packet and the falsified packet distribute the similar hash (0xABC123), however the attacker’s packet is added after the legitimate one. The server has no way to distinguish among the two because their hash values are the similar that simulating the impacts of a birthday attack.
- Tracing and Visualization:
- A trace file (birthday_attack.tr) records the network events that encompassing the packet transmission from both the client and the attacker.
- A NAM file (birthday_attack.nam) is made to envision the network behavior and the attack.
Step 5: Run the Simulation
- We can save the script as birthday_attack.tcl.
- Execute the script in NS2:
ns birthday_attack.tcl
It will generate two files:
- birthday_attack.tr: A trace file including the packet-level information.
- birthday_attack.nam: A NAM file for envisioning the simulation in NAM.
Step 6: Visualize the Simulation Using NAM
To envision the simulation, we can utilize NAM:
nam birthday_attack.nam
In NAM, we will observe:
- The client transmitting a legitimate packet with a hash.
- The attacker transmitting a falsified packet with the similar hash, which replicating a birthday attacks in which the server cannot distinguish among the two.
Step 7: Analyze the Trace File
The trace file (birthday_attack.tr) will log the below details:
- Packet transmissions: Information of the packets transmitted from both the legitimate client and the attacker.
- Hash collision: Both packets will have the similar hash value that mimicking a birthday attack collision.
We can utilize AWK, Python, or custom scripts to envision the trace file and extract related parameters such as packet timing, packet collisions, or server behavior.
Step 8: Enhance the Simulation
Here are few ways to expand or improve the simulation:
- Simulate Hash Verification: Insert a mechanism at the server to verify hash values and identify the collisions.
- Introduce Defense Mechanisms: Execute mechanisms such as cryptographic hashing with longer hash lengths or arbitrary salts to minimize the likelihood of collisions.
- Simulate Larger Networks: Insert more clients and attackers to replicate a more complex environment.
- Measure Impact: Assess the server’s behavior in managing several packets with same hash values and how it could lead to susceptibilities.
In this approach, we successfully walk you through the entire replication method of Birthday Attack projects that were simulated using NS2 simulator. We are furnished to deliver more insights according to your needs.
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