Hashing

• What does a hashing function do?

  Transforms a string into a fixed length value
• What is a popular hashing algorithm?

  SHA1
• What happens to the hash value if the original message changes slightly?

  It produces a totally different hash value
• How does hashing differ from encryption?

  Hashing is a one-way process
• Can you retrieve the original value from a hashed value?

  No, it is a one-way process
• Why is hashing ideal for storing passwords?

  It prevents passwords from being read
• What happens when a user logs into an account?

  The system checks the hashed password
• What is a consequence of storing passwords in plain text?

  Hackers can easily read the passwords
• How does hashing protect passwords during login?

  It sends hashed values instead of plain text
• What is the time complexity of hashing for searching data?

  Constant $O(1)$ time complexity
• What are the uses of hashing?

  • Preventing password exposure
  • Quick searching in data structures
  • Insertion and deletion of data
• How does hashing improve data retrieval in memory?

  It allows immediate item location without sorting
• What is the key question to answer after watching the video?

  What is hashing?