15 - What is Time-based One Time Passwords?

Youtube Video

TOTP

  • Randomness
  • RNGs
  • PRNGs
  • Seeded PRNGs
  • Hash Functions
  • What are they / Where are they used?
  • Important to keep in mind that there are crytpographic and non-cryptographic hash functions
  • TOTP combines Seeded PRNGs and Cryptographic Hash Functions to generate predictable, “random” codes using a seed and the current time.
  • As long as your device has the correct time, you can generate the correct code
  • This seed is present on your device (usually loaded through a QR code) and on the server.
  • When you log in, the server knows what the code should be (based on current time), so it can confirm that you have the right code

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