Hash Applications

Storing plaintext password in a database

If an attacker gains access to the database, they can impersonate any user

If an attacker gains access to the database, they can use precomputed lookup tables of hashes of frequently used passwords to find matches

<p>Using salt to store hashed password in a database</p> Signup and view all the answers

<p>A distributed ledger for storing cryptocurrency transactions</p> Signup and view all the answers

<p>Any changes to a block's content would require altering all subsequent blocks</p> Signup and view all the answers

<p>A scheme employed in Bitcoin and anti-spam systems that uses hash functions to ensure that creating a valid message requires a certain amount of computing resources</p> Signup and view all the answers

<p>To append to a file or message and compute a hash</p> Signup and view all the answers

<p>To check new transactions, build a new block, compute a proof-of-work, and write the successful nonce into the block</p> Signup and view all the answers

<p>To produce a nonce that satisfies the proof-of-work condition to send a message</p> Signup and view all the answers

<p>They are rejected by the receiver</p> Signup and view all the answers

<p>To adjust the difficulty of proof-of-work</p> Signup and view all the answers

<p>An attacker can impersonate any user</p> Signup and view all the answers

<p>Using salt</p> Signup and view all the answers

<p>To add randomness to the hash function</p> Signup and view all the answers

<p>A distributed ledger</p> Signup and view all the answers

<p>Permissionless blockchain allows anybody to join</p> Signup and view all the answers

<p>To prevent spam emails from being sent</p> Signup and view all the answers

<p>To build a new block and compute a proof-of-work</p> Signup and view all the answers

<p>To add randomness to the hash function</p> Signup and view all the answers

<p>The email is rejected by the receiver</p> Signup and view all the answers

<p>To make it more difficult for miners to validate transactions</p> Signup and view all the answers

<p>Storing hashed password is more secure</p> Signup and view all the answers

<p>To ensure the security of the blockchain</p> Signup and view all the answers

<p>Ciphertext only, known plaintext, chosen plaintext, chosen ciphertext, samples of previous signatures or message authentication codes.</p> Signup and view all the answers

<p>Finding the plaintext, the key, creating a digital signature or creating a message authentication code.</p> Signup and view all the answers

<p>It depends on the definition of security being used.</p> Signup and view all the answers

<p>It means that breaking the cipher is unfeasible (too time/resource consuming) based on the currently available algorithms and computing power.</p> Signup and view all the answers

<p>It means that breaking the cipher is impossible (even with unlimited time/resources).</p> Signup and view all the answers

<p>It means that the ciphertext leaks no information about the plaintext (except the length); guessing the plaintext has the same chances of success after having seen the ciphertext as it had before seeing it.</p> Signup and view all the answers

<p>It means that there is no efficient algorithm that can be used by the attacker to succeed with reasonably high probability.</p> Signup and view all the answers

<p>Mainly public key cryptography.</p> Signup and view all the answers

<p>No.</p> Signup and view all the answers

<p>Computational security only in the sense that no attack has succeeded in a reasonable amount of time. However, there is no proof that no efficient attack will be found.</p> Signup and view all the answers

<p>A cipher that has perfect secrecy.</p> Signup and view all the answers

<p>Because it is expensive.</p> Signup and view all the answers