Demystifying Hashing: Learn the Basics and Examples

Table of Contents

1. Introduction
2. Storing Passwords: Plain Text Format
3. Storing Passwords: Encryption and Decryption
4. Storing Passwords: Hashing
5. How Hashing Works
6. Hash Functions
   1. Main Input and Digest
   2. Reversibility of Hashes
   3. Secure Hash Algorithms
7. Requirements of a Hash Function
   1. Speed and Performance
   2. Balance of Speed and Security
   3. Bit Dependency
8. Hash Collisions and Salting
   1. Definition of Hash Collision
   2. Risks and Common Passwords
   3. The Process of Salting
9. Peppering
   1. Definition of Peppering
   2. How Peppering Works
   3. Combination of Salting and Peppering
10. Conclusion

Storing Passwords: Plain Text Format

When it comes to storing passwords, website administrators have different alternatives. The most insecure option is storing passwords in plain text format. In this scenario, anyone in the company can easily read the passwords. This poses a significant risk as a single hack or data breach can expose all the account credentials without much effort. Consequently, storing passwords in plain text format is not recommended due to the lack of security and privacy it provides.

Storing Passwords: Encryption and Decryption

To address the security concerns of storing passwords in plain text, website owners can choose to encrypt passwords using encryption and decryption keys. When a user creates an account and sets a password, the password is encrypted and stored on the server. Encryption ensures that the passwords are not easily accessible to unauthorized personnel within the company. However, this method also has its drawbacks. In the event of a data breach or server hack, both the encrypted passwords and decryption keys could be leaked, creating a single point of failure.

Storing Passwords: Hashing

A more secure option for storing passwords is hashing. Hashing involves storing passwords after scrambling them completely, with no way to decrypt them. Only the hashed values are stored on the server, ensuring that the website administrators cannot access users' passwords in plain text. Hashing provides an added layer of security, making it harder for malicious actors to retrieve original passwords even if they gain unauthorized access to the server. As a result, hashing is widely considered the industry standard for password storage.

How Hashing Works

Hashing is the process of scrambling a piece of information or data beyond recognition. It involves using hash functions, which are algorithms that perform mathematical operations on the input data. The output generated after passing the plaintext information through the hash function is called the hash value or digest. Unlike encryption, hashes are meant to be irreversible, meaning there is no decryption key to convert the digest back to its original value. However, certain hashing algorithms have been compromised due to the computational advancements of modern computers.

Hash Functions

Hash functions are sets of mathematical calculations that operate on two blocks of data. The main input is broken down into two blocks of similar size, with the block size depending on the algorithm being used. Hash functions are designed to be one-way, meaning they should not be reversible. Secure algorithms like the SHA family of algorithms produce digests of various sizes, such as 128 bits for MD5 and 256 bits for SHA-256. The hash value must remain the same for the same input, irrespective of how many times the calculations are carried out.

Requirements of a Hash Function

There are certain requirements that a hash function must meet to be considered secure and reliable. Firstly, it should be quick enough to encrypt large amounts of data at a relatively fast pace. However, it should not be too fast, as this could make the function susceptible to brute-force attacks. A balance must be struck to allow the hash function to handle large volumes of data without compromising security.

Additionally, a hash function should be dependent on each bit of the input. Regardless of the input type (text, audio, video, etc.), even a small change in a single character should result in a distinctly different hash value. This ensures that each password stored has a unique digest. Hash collisions, where two different inputs produce the same hash value, can be minimized by using techniques like salting.

Hash Collisions and Salting

A hash collision occurs when two different inputs produce the same hash value. While it may seem rare for two users to have exactly the same password, it is more common than one would expect. Many users tend to use the same passwords repeatedly, and with the vast number of user accounts across different websites, the risks of hash collisions increase.

To reduce hash collisions, the process of salting is employed. Salting involves adding a random keyword to the end of the input before it is passed to the hash function. This random keyword, known as the salt value, is unique for each user on the system. Even if two users have the same password, their salt values will differ, resulting in distinct digests. By storing the salt values alongside the passwords, the entire verification process becomes faster.

Peppering

Another technique to enhance security is peppering. Peppering involves adding a random string of data to the input before passing it to the hash function. Unlike salt values, which are unique for each user, the pepper is common for all users in the database. The pepper is not stored on the servers but is typically hard-coded into the website's source code. This way, even if the servers are compromised, the hackers will not have the necessary pepper to crack the passwords. A combination of both salting and peppering can further improve the security of stored passwords.

Conclusion

In conclusion, the storing of passwords plays a crucial role in maintaining security and protecting user privacy. Hashing is considered the industry standard for password storage due to its irreversible nature. While encryption and plain text formats have their drawbacks, hashing ensures that user credentials are safe from snooping website administrators and significantly minimizes the risks associated with data breaches. By employing additional techniques like salting and peppering, the security of stored passwords can be further enhanced. It is essential for website owners and administrators to implement secure hashing practices to safeguard user accounts and sensitive information.