2.2 Hash Pointers and Data Structures

Question 1

Hash pointer: What does it do?

Answer 1

allows us to verify that the information has not changed
but: it does not contain information to the location of the data enriched with a cryptographic hash of it

Question 2

Blockchain is …

Answer 2

a linked list of hash pointers is typically referred to as blockchain. Hash pointers are used instead of normal pointers. (WHY DOES IT WORK?)

Question 3

Merkle trees: a data structure using …, i.e. a ….
 They are an efficient way and secure way to…

Answer 3

cryptographic hashes
binary tree with hash pointers
verify large data structures

Question 4

Proof of Membership vs Proof of Non-Membership in a Merkle Tree

Answer 4

an efficient way to prove that a certain block is contained in a Merkle tree (Proof of Membership) and to prove that a certain data block is not contained in a sorted Merkle tree (Proof of non-Membership).


Question 5

Why is proof of membership efficient in a merkle tree?

The Merkle tree is efficient for this because…

Answer 5

we only have to check the hashes of the corresponding nodes and leaves, enabling verification in log(n) time.