reading-notes

Cryptography

Reading Questions

  1. What is the basic principle behind the Caesar Cipher, and how was it used historically?

    The basic principle of the Caesar Cipher is to shift the letters a number of places in the alphabet. It was used historically to transmit military messages, mainly in the Roman Era.

  2. What are the key differences between symmetric and asymmetric encryption? How is asymmetric used in secure communication today?

    • Symmetric:
      • Uses a single key to encrypt and decrypt
      • Requires a secure way to share the key
      • Most commonly used in data at rest like hard drives and databases
    • Asymmetric:
      • Uses two different keys for encryption and decryption
      • Public key encrypts, private key decrypts
      • Used primarily for transmitting information, like email and HTTPS

  3. How do computers generate random numbers, and what are the differences between true random number generation (TRNG) and pseudo-random number generation (PRNG)? Discuss their use cases in cryptography.

    • TRNG:
      • True random number (generation)
      • Uses unpredictable data or entropy
      • Gathers random data from environment
      • Could be based on things like when a user pressed a key, moved a mouse, etc.
    • PRNG:
      • Pseudorandom number (generation)
      • Uses a seed value and an algorithm to create
      • Not secure for use in cryptography unless combined with other methods

  4. What’s the difference between encryption and decryption? Explain with an analogy.

    Encryption and decryption can be thought of like a puzzle. When you first get a puzzle, all the pieces are jumbled and out of order like encryption. You then put the pieces together to create the resulting image, like decryption.

Things I want to know more about

References