After completing this experiment, you will be able to:

1. Understand Digital Signature Fundamentals

   • Comprehend the basic principles of digital signatures and their role in cryptographic security
   • Recognize the importance of authentication, integrity, and non-repudiation in digital communications
   • Understand why digital signatures are essential for secure electronic transactions

2. Master Digital Signature Operations

   • Perform hash generation using the SHA-1 algorithm on plaintext messages (used here for simplicity of demonstration; note that SHA-1 is deprecated for security-critical use in modern systems — see the Theory page for details)
   • Execute RSA-based digital signature creation using private keys
   • Understand the relationship between hash functions and digital signature schemes

3. Analyze RSA Key Parameters

   • Compare the small RSA key sizes (512-bit vs 1024-bit) used for demonstration in this experiment against the 2048-bit minimum recommended for production use today, and understand their security implications
   • Understand the significance of different public exponents (e = 3 vs e = 65537/F4), including why very small exponents like e = 3 require careful padding to avoid forgery attacks
   • Evaluate the trade-offs between key size and computational efficiency

4. Develop Cryptographic Implementation Skills

   • Apply the complete digital signature process from plaintext to signature
   • Convert between different encoding formats (hexadecimal and base64)
   • Troubleshoot common issues in digital signature implementation

5. Apply Practical Knowledge

   • Implement digital signature operations step-by-step
   • Solve real-world authentication and integrity challenges
   • Evaluate the security and practical applications of RSA-based digital signatures
   • Recognize real-world application domains that depend on digital signatures, such as:
     • Software distribution (code signing)
     • Financial transactions and legal/contract documents
     • Secure web browsing (TLS/SSL certificate signing)

6. Appreciate Cryptographic Workflow: Understand the step-by-step process from plaintext message to verifiable digital signature.

7. Connect Theory to Practice: Bridge the gap between theoretical cryptographic concepts and their practical implementation in digital signature systems.