How to Implement Cryptographic Hashing in OMNeT++
To implement the cryptographic hashing in OMNeT++ has includes making a simulation situation where network nodes use cryptographic hash functions to make sure data integrity, check authenticity, and protect communication. This functions take an input or “message” and send a fixed-size string of bytes, normally a digest that is one and only to each unique input.
Steps to Implement Cryptographic Hashing in OMNeT++
- Set up the Network Environment
Initially, describe the network topology where nodes will communicate using cryptographic hashing. The topology might contain:
- Client Nodes: These nodes will create data and make a hash to make sure the integrity of the data.
- Server Nodes: These nodes will get the data and validate its integrity by comparing the received hash with the hash of the received data.
- Intermediary Nodes (Optional): Nodes that might change or check data to mimic integrity verification.
Network Topology Setup:
Describe the basic modules for the network:
simple ClientNode
{
parameters:
@display(“i=block/pc”);
gates:
inout ethg;
}
simple ServerNode
{
parameters:
@display(“i=block/server”);
gates:
inout ethg;
}
simple IntermediaryNode
{
parameters:
@display(“i=block/router”);
gates:
inout ethg[2]; // Assume a node with multiple connections
}
network HashingNetwork
{
submodules:
client: ClientNode;
server: ServerNode;
intermediary: IntermediaryNode;
connections:
client.ethg <–> intermediary.ethg[0];
intermediary.ethg[1] <–> server.ethg;
}
- Implement Cryptographic Hashing in the Client Node
The client node will make data, calculate its hash using a cryptographic hash function like SHA-256, and send both the data and its hash to the server.
Client Node Hashing Logic:
#include <openssl/sha.h> // Include OpenSSL for SHA-256
class ClientNode : public cSimpleModule {
protected:
virtual void initialize() override {
// Generate data and its hash
std::string data = “SensitiveData”;
std::string hash = computeHash(data);
// Send data and hash to the server
sendDataAndHash(data, hash);
}
virtual void handleMessage(cMessage *msg) override {
// Handle incoming messages (if any)
}
std::string computeHash(const std::string &data) {
unsigned char hash[SHA256_DIGEST_LENGTH];
SHA256((unsigned char*)data.c_str(), data.length(), hash);
// Convert the hash to a string
std::stringstream ss;
for (int i = 0; i < SHA256_DIGEST_LENGTH; ++i) {
ss << std::hex << std::setw(2) << std::setfill(‘0’) << (int)hash[i];
}
return ss.str();
}
void sendDataAndHash(const std::string &data, const std::string &hash) {
cPacket *dataPacket = new cPacket(“DataWithHash”);
dataPacket->addPar(“data”) = data;
dataPacket->addPar(“hash”) = hash;
send(dataPacket, “ethg$o”);
EV << “Client sent data with hash: ” << hash << endl;
}
};
- Implement Hash Verification in the Server Node
The server node will get the data and hash, calculate the hash of the received data, and compare it with the received hash to check integrity.
Server Node Verification Logic:
#include <openssl/sha.h> // Include OpenSSL for SHA-256
class ServerNode : public cSimpleModule {
protected:
virtual void handleMessage(cMessage *msg) override {
cPacket *pkt = check_and_cast<cPacket*>(msg);
std::string receivedData = pkt->par(“data”).stringValue();
std::string receivedHash = pkt->par(“hash”).stringValue();
// Compute the hash of the received data
std::string computedHash = computeHash(receivedData);
// Verify the integrity of the data
if (computedHash == receivedHash) {
EV << “Data integrity verified. Hash matches: ” << computedHash << endl;
} else {
EV << “Data integrity failed. Computed hash: ” << computedHash
<< ” does not match received hash: ” << receivedHash << endl;
}
delete pkt;
}
std::string computeHash(const std::string &data) {
unsigned char hash[SHA256_DIGEST_LENGTH];
SHA256((unsigned char*)data.c_str(), data.length(), hash);
// Convert the hash to a string
std::stringstream ss;
for (int i = 0; i < SHA256_DIGEST_LENGTH; ++i) {
ss << std::hex << std::setw(2) << std::setfill(‘0’) << (int)hash[i];
}
return ss.str();
}
};
- Implement (Optional) Intermediary Node
If we want to mimic potential tampering, we can execute an intermediary node that might change the data, resulting in a hash mismatch at the server.
Intermediary Node Logic:
class IntermediaryNode : public cSimpleModule {
protected:
virtual void handleMessage(cMessage *msg) override {
cPacket *pkt = check_and_cast<cPacket*>(msg);
// Optionally alter the data (simulating tampering)
if (uniform(0, 1) < 0.5) { // 50% chance to alter data
std::string alteredData = pkt->par(“data”).stringValue() + “_tampered”;
pkt->par(“data”) = alteredData;
EV << “Intermediary tampered with the data: ” << alteredData << endl;
}
send(pkt, “ethg$o”);
}
};
- Simulate and Evaluate the Cryptographic Hashing
Run simulations to assess the performance and rightness of the cryptographic hashing execution:
- Verify Integrity: Make sure that the server appropriately confirms the integrity of the data using the received hash.
- Test with Tampering: If using the intermediary node, verify how tampered data leads to a hash variance, and the server discovers the integrity failure.
- Measure Performance: Calculate the above introduced by hashing and its influence on communication latency.
- Enhance Security and Realism
To further improve the execution:
- Use Different Hash Functions: Discover other cryptographic hash functions like SHA-1, SHA-512, or MD5 though MD5 is not suggested for security purposes.
- Combine with Encryption: Execute setups where hashing is joined with encryption to make sure both data integrity and confidentiality.
- Simulate Large Networks: Increase the network topology to contain several clients, servers, and intermediary nodes, and mimic difficult interactions.
In the above procedures are very helpful to learn how to execute the Cryptographic hashing using the OMNeT++ tool. We plan to elaborate how to implement Cryptographic hashing will operates in other simulation tools. To implement cryptographic hashing in the OMNeT++ tool, we offer comprehensive guidance backed by our expert technical team