Why Speed Kills Password Security

The fundamental problem with MD5, SHA-1, and SHA-2 for password hashing is their computational efficiency. These algorithms were designed to quickly process large amounts of data—a desirable property for file integrity checking or digital signatures but catastrophic for password security. Modern hardware can test billions of password candidates per second, making even complex passwords vulnerable to brute force attacks.

GPU acceleration multiplies the threat exponentially. Graphics cards excel at parallel computation, and password hashing is embarrassingly parallel—each password guess is independent. A single high-end GPU can compute over 100 billion MD5 hashes per second, 40 billion SHA-1 hashes per second, or 10 billion SHA-256 hashes per second. Cryptocurrency mining has driven GPU development that coincidentally benefits password cracking.

def gpu_cracking_estimates():
    """Estimate GPU cracking capabilities against different hash functions"""
    
    # Approximate hash rates for high-end GPU (e.g., RTX 4090)
    gpu_rates = {
        'MD5': 100_000_000_000,      # 100 billion/sec
        'SHA-1': 40_000_000_000,      # 40 billion/sec
        'SHA-256': 10_000_000_000,    # 10 billion/sec
        'SHA-512': 3_000_000_000,     # 3 billion/sec
        'bcrypt (cost=10)': 150_000,  # 150 thousand/sec
        'scrypt (N=16384)': 5_000,    # 5 thousand/sec
        'Argon2id': 10_000            # 10 thousand/sec
    }
    
    password_space = 62**8  # 8-character alphanumeric
    
    print("Time to crack 8-character alphanumeric password on high-end GPU:\n")
    
    for algo, rate in gpu_rates.items():
        seconds = password_space / rate
        
        if seconds < 60:
            print(f"{algo:.<20} {seconds:.1f} seconds")
        elif seconds < 3600:
            print(f"{algo:.<20} {seconds/60:.1f} minutes")
        elif seconds < 86400:
            print(f"{algo:.<20} {seconds/3600:.1f} hours")
        elif seconds < 31536000:
            print(f"{algo:.<20} {seconds/86400:.1f} days")
        else:
            print(f"{algo:.<20} {seconds/31536000:.1f} years")
    
    print("\nNote the dramatic difference between fast hashes and password-specific algorithms!")

gpu_cracking_estimates()