RSA Algorithm
Understanding the RSA encryption and decryption process.
RSA Algorithm is a free Cryptology Academy lesson on CoddyKit — lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Cryptology Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
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RSA Algorithm
RSA is a widely used asymmetric encryption algorithm that ensures secure communication using public and private keys.
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How RSA Works
RSA relies on the mathematical difficulty of factoring large prime numbers. It generates a key pair:
- A public key for encryption.
- A private key for decryption.
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Key Generation
- Choose two large prime numbers (p and q).
- Compute n = p × q.
- Calculate Euler’s totient function φ(n) = (p-1) × (q-1).
- Select an encryption exponent (e), typically 65537.
- Compute the private key (d) using modular inverse.
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Encryption Process
- Convert plaintext to numerical form.
- Use the public key (n, e) to compute ciphertext: ( C = M^e mod n ).
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Decryption Process
- Use the private key (n, d) to compute plaintext: ( M = C^d mod n ).
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Security of RSA
- Relies on the difficulty of factoring large numbers.
- Longer key sizes (e.g., 2048-bit) provide higher security.
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Use Cases
- Secure email communication.
- Digital signatures.
- SSL/TLS encryption for secure web browsing.
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Limitations
- Slower than symmetric encryption.
- Vulnerable if weak keys are used.
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Summary
- RSA is an asymmetric encryption algorithm.
- It uses public and private keys for secure communication.
- Its security is based on the difficulty of factoring large prime numbers.
Frequently asked questions
Is the “RSA Algorithm” lesson free?
Yes — the full text of “RSA Algorithm” is free to read here on the web, and the Cryptology Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Cryptology Academy course, upgrade to CoddyKit PRO.
What will I learn in “RSA Algorithm”?
Understanding the RSA encryption and decryption process. You practise Cryptology Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Cryptology Academy?
No prior experience is required. Cryptology Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “RSA Algorithm” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Cryptology Academy lesson?
Yes. Every Cryptology Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- RSA Algorithm
- Elliptic Curve Cryptography
- Key Exchange Protocols