what is Hashing or Hash Algorithm

what is Hashing or Hash Algorithm

  2월 17, 2022    Eunhan's library

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Hash Algorithm

Definition

1. Hashing or Hash function

one of mathematical function that converts an input of arbitrary length into an encrypted output of a fixed length.

Example of Hash function

insert "A" --Hash Function--> return "123"
insert "ABG" --Hash Function--> return "778"
insert "HEU" --Hash Function--> return "998"

2. Hash Data Structure

Programmers used hash function to create many data structures.

Examples of Java Hash Data Structures

• Hash set
• LinkedHashSet
• Hash table
• Hash map
• LinkedHashMap
• TreeSet
• ConcurretHashMap

3. Hash Algorithm

Programmers used the hash data structures to solve problems.
The way to solving problems is Hash algorithm

Characteristics

• Hash Data Structures need more memories than total list n
• The worst case, Hash algorithm can be slow because of hash collision

Properties

• Hash crash or hash collision
• efficiency
• uniformity
• collision resistance
• pre-image resistance
• second pre-image resistance

Hash algorithms can be used as..

• encryption
• store values
• verify same files or not