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# Password Protection

## Introduction

![](https://1374779285-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MFW3x2aqEO8GF2kr3VU%2Fuploads%2FCAj8sQ6LZTnipw2Qu6EY%2Fimage.png?alt=media\&token=247a7ef4-1f7b-402c-b9c3-7937deeecaaf)

* Password will not be stored into database directly
* Password will be hashed with salt in one-way direction and store in db
* The stored hashed will used to compare the user entered password to see whether it is matched or not

## Salt

* a salt is a unique, randomly generated string that is added to each password as part of the hashing process
* Generate unique hash value to prevent from hacker attack

## Hacker Attack

### Dictionary attack

* A dictionary attack is a brute-force method that tries to guess a password by using a list of common or likely words, phrases, or combinations.
* For example, if you want to crack the password of a user named Alice, you might try words like alice, alice123, alice1984, or alice!@#. The dictionary attack can also use variations of these words, such as changing the case, adding numbers or symbols, or using leet speak.
* Simple and Fast if the dictionary size is small

### Rainbow table attack

![](https://1374779285-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MFW3x2aqEO8GF2kr3VU%2Fuploads%2F1oSXK3mki9KFYoRgbZ5n%2Fimage.png?alt=media\&token=66b190b3-dc49-4a4e-844e-c2ffe3290ae6)

* A rainbow table is a precomputed table that stores the hashes and the corresponding plain texts of a large set of possible passwords.
* It requires lots of space for storage
* Doing reverse-lookup to find whether the hashed password is existed in the table or not and then find the plain text
* The efficiency will be higher if the dictionary size is large