How to Implement Network Multi Party Computation in NS2

To implement the Network Multi-Party Computation (MPC) in NS2 encompasses to simulate communication amongst several parties (nodes) to securely estimate a function without exposing their personal data to one another. We have to replicate communication infrastructure for an MPC protocol yet not the original cryptographic computations because ns2 is a network simulator which prototypes a data transmission through the network.

In an MPC simulation, each node indicates a party, and they interchange messages (encrypted or otherwise) to define a joint function. The core of MPC is secure communication, making certain that each node can contribute without illuminating private data.

Steps for Simulating MPC Communication in NS2:

  1. Set Up the Network Topology: Model the parties as nodes in the network.
  2. Implement Secure Communication: TCP or UDP is used to mimic message exchanges amongst the nodes as fragment of the MPC protocol.
  3. Simulate Round-Based Communication: MPC protocols usually proceed in rounds, where each party sends and receives data in each round.
  4. Add Failure Handling (Optional): Simulate more realistic environment by adding a network failures or message drops.

Key Elements for an MPC Simulation in NS2:

  1. Nodes as Parties: Each node indicates one party in the MPC protocol.
  2. Message Exchange: Simulate the communication amidst parties using TCP/UDP to interchange messages during the computation process.
  3. Synchronous or Asynchronous Communication: Replicate if the communication is synchronous (all parties send and receive in the same round) or asynchronous (parties send/receive at various times).
  4. Trace Analysis: Observe message exchanges, delays, packet losses, and performance metrics by evaluating the trace files.

Example: Simulating a Simple Multi-Party Communication Setup in NS2

We will simulate a network of 4 parties communicating in rounds. Each party delivers a message to every other party, and the simulation will model this interaction for a simple MPC protocol.

Example TCL Script for Simulating Multi-Party Communication in NS2:

# Create a new simulator instance

set ns [new Simulator]

# Define output trace file for logging events

set tracefile [open mpc_simulation.tr w]

$ns trace-all $tracefile

# Define animation file for NAM (optional)

set namfile [open mpc_simulation.nam w]

$ns namtrace-all $namfile

# Create network nodes (4 parties)

set party1 [$ns node]

set party2 [$ns node]

set party3 [$ns node]

set party4 [$ns node]

# Create duplex links between all parties to simulate the communication network

$ns duplex-link $party1 $party2 10Mb 10ms DropTail

$ns duplex-link $party1 $party3 10Mb 10ms DropTail

$ns duplex-link $party1 $party4 10Mb 10ms DropTail

$ns duplex-link $party2 $party3 10Mb 10ms DropTail

$ns duplex-link $party2 $party4 10Mb 10ms DropTail

$ns duplex-link $party3 $party4 10Mb 10ms DropTail

# Define UDP agents for each party to simulate message exchange

set udp_party1 [new Agent/UDP]

$ns attach-agent $party1 $udp_party1

set udp_party2 [new Agent/UDP]

$ns attach-agent $party2 $udp_party2

set udp_party3 [new Agent/UDP]

$ns attach-agent $party3 $udp_party3

set udp_party4 [new Agent/UDP]

$ns attach-agent $party4 $udp_party4

# Define Null agents as sinks to receive the messages at each party

set sink_party1 [new Agent/Null]

$ns attach-agent $party1 $sink_party1

set sink_party2 [new Agent/Null]

$ns attach-agent $party2 $sink_party2

set sink_party3 [new Agent/Null]

$ns attach-agent $party3 $sink_party3

set sink_party4 [new Agent/Null]

$ns attach-agent $party4 $sink_party4

# Connect UDP agents to Null agents (simulating message passing in rounds)

$ns connect $udp_party1 $sink_party2

$ns connect $udp_party1 $sink_party3

$ns connect $udp_party1 $sink_party4

$ns connect $udp_party2 $sink_party1

$ns connect $udp_party2 $sink_party3

$ns connect $udp_party2 $sink_party4

$ns connect $udp_party3 $sink_party1

$ns connect $udp_party3 $sink_party2

$ns connect $udp_party3 $sink_party4

$ns connect $udp_party4 $sink_party1

$ns connect $udp_party4 $sink_party2

$ns connect $udp_party4 $sink_party3

# Define traffic generators to simulate MPC message exchange between parties

set traffic1 [new Application/Traffic/CBR]

$traffic1 attach-agent $udp_party1

$traffic1 set packetSize_ 512   # Set the packet size for messages

$traffic1 set rate_ 1Mb         # Set the rate for message sending

set traffic2 [new Application/Traffic/CBR]

$traffic2 attach-agent $udp_party2

$traffic2 set packetSize_ 512

$traffic2 set rate_ 1Mb

set traffic3 [new Application/Traffic/CBR]

$traffic3 attach-agent $udp_party3

$traffic3 set packetSize_ 512

$traffic3 set rate_ 1Mb

set traffic4 [new Application/Traffic/CBR]

$traffic4 attach-agent $udp_party4

$traffic4 set packetSize_ 512

$traffic4 set rate_ 1Mb

# Schedule the message exchanges to simulate communication in MPC rounds

$ns at 0.5 “$traffic1 start”

$ns at 1.0 “$traffic2 start”

$ns at 1.5 “$traffic3 start”

$ns at 2.0 “$traffic4 start”

# Stop the traffic at 5.0 seconds

$ns at 5.0 “$traffic1 stop”

$ns at 5.0 “$traffic2 stop”

$ns at 5.0 “$traffic3 stop”

$ns at 5.0 “$traffic4 stop”

# Schedule simulation end time

$ns at 6.0 “finish”

# Define finish procedure to close trace files and run NAM visualization

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam mpc_simulation.nam &

exit 0

}

# Run the simulation

$ns run

Explanation of the Script:

  1. Network Topology Setup:
    • Four nodes (party1, party2, party3, party4) denote the parties involved in the multi-party computation.
    • Duplex links amongst each pair of parties simulate the communication channels between the participants, with a bandwidth of 10Mb and a delay of 10ms.
  2. Message Exchange Simulation:
    • UDP agents are stated for each party, indicating the channels through which messages are interchanged.
    • Null agents are included to each party to obtain the messages sent by other parties.
  3. Traffic Generation:
    • CBR (Constant Bit Rate) traffic generators replicate the original message exchanges amongst the parties. Each party sends a fixed-size packet (representing an MPC message) at a rate of 1Mb per second to every other party.
  4. Round-Based Communication:
    • The traffic starts at various times to simulate rounds of communication: party1 begins sending messages at 0.5 seconds, party2 at 1.0 seconds, and so on.
    • The communication continues until 5.0 seconds, after which the traffic is terminated.
  5. Simulation Output:
    • The trace file (mpc_simulation.tr) will log the message exchanges amidst the parties.
    • The NAM file (mpc_simulation.nam) permits for visualizing the communication between the parties.
  1. Analyzing the Trace File

The trace file contains detailed information about message transmission, reception, delays, and packet drops. You can use this data to assess:

  • Latency: Compute the time taken for messages to move amongst parties.
  • Packet Loss: Track any packets that were dropped during communication.
  • Message Rounds: Validate that messages are being interchanged based on the protocol’s rounds.

You can write scripts in Python or awk to parse and analyze the trace file.

  1. Adding Failures and Delays

To simulate a more realistic scenario, you can launch network failures (includes dropping messages or disconnecting links) or increased latency to monitor how the MPC protocol acts in these conditions.

Example: Simulating Link Failure

# Simulate a link failure between party1 and party3 at 2.5 seconds

$ns at 2.5 “$ns rtmodel-at 2.5 down $party1 $party3”

$ns at 4.0 “$ns rtmodel-at 4.0 up $party1 $party3”

This presents a temporary failure in the link amongst party1 and party3, and the communication is restored at 4.0 seconds.

  1. Advanced MPC Simulation (Security and Data Integrity)

NS2 concentrates on network-level simulations, so to simulate secure multi-party computation (MPC) protocols, you can:

  • Model message encryption and secure message exchange amidst parties by assuming that messages are encrypted.
  • Track whether parties successfully interchange all demanded messages in each round.
  • Model data integrity by making certain that packets are neither modified nor dropped during transmission (simulating integrity checks).

Through the structured and elaborated process, you can be able to learn the concept and focused on the implementation of Multi Party Computation in the network simulation environment using the ns2 tool. We also provided snippet codes and its advanced techniques for you. We have everything you need to give you the best topics and timely support. Stay connected with us for the best  implementation results.