#include <stdio.h>

int main(void) {
    puts("=== Toy Simulation of Certificate-Based Authentication ===");
    puts("Remote service ExampleCorp wants to prove its identity.");
    puts("It presents a certificate containing its public key, signed by TrustedCA.");
    puts("Local machine already holds TrustedCA's public key (pre-installed).");
    puts("Signature verification succeeds.");
    puts("Public key of ExampleCorp is now trusted for this session.");
    puts("Encrypted channel can be established.");
    puts("Remember: the remote OS itself may still be compromised.");
    return 0;
}