06 - Different uses of hashing

 1. Hash functions are so named because they appear to scramble input.



 2. Hashing can be defined as …

  overheating of a CPU

  the mapping of data of arbitrary size to a fixed size

  the encryption of each bite of data using a key

  the translation of one human language into another

 3. A cryptographic hashing algorithm will be a one-way function. What does this mean?

  It is easier to compute as an input than to invert

  It can be inputed and inverted easily

  It can only be used once

  It can only hash a specific form of data

 4. What is the hash total (also known as a checksum or digest)?

  The number of unencrypted characters in decimal

  The number of hash operations executed

  The mathematical value of the unencrypted data

  The meaure of complexity of the hashing algorithm

 5. Hashing is often used to protect online user passwords stored in a database.



 6. Digital signatures usually create a one-way hash value for a signature or document and …

  encrypt the hash value using a Caesar cipher

  publish an unencrypted hash value

  encrypt the hash value using a private key

  ensure the hash value is sent to one recipient only

 7. The recipient of the digital signature can then use the public key to …

  decrypt the hash value and compare it against a reproduced hash value

  exchange it for a private key

  decrypt the hash value and transmit this value back to the sender to verify

  encrypt the hash value again for additional security

 8. If the signature or document has been changed, the hash values will be …

  different if the changes are significant

  impossible to decrypt

  still identical


 9. A digital certificate can be used for which of these purposes?

  To reward websites with good security

  To encypt html

  To verify a public key

  To explain a hashing algorithm

 10. The digital certificate will include a digital signature of the issuing Certificate Authority.