Hashing is a computer science process that transforms any size input of data into a fixed-length output. This output, called a hash code or hash value, is typically a string of characters. Hashing is useful for data retrieval, security measures, and data comparison, since even small changes in input data will result in significantly different hash values.


The phonetics of the keyword “Hashing” is /ˈhæʃɪŋ/.

Key Takeaways

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  1. Go-to Tool for Speed: Hashing is primarily used for quick data retrieval. It uses a hash function that converts an input or ‘key’ into a numerical value, which can be used to look up the item in a database. This makes data operations extremely quick and efficient.
  2. Collision Handling: There may sometimes occur a situation where two keys hash to the same value, a scenario known as a ‘collision’. There are several ways to handle collisions, such as chaining, which is adding both values to the same slot, or open addressing, which finds the next available slot.
  3. Applications in Various Fields: Hashing has wide applications in various fields such as databases, caches, password security, data synchronization, error detection and prevention etc. Its ability to quickly index large amounts of data make it a crucial part of modern computing.



Hashing is a crucial concept in technology, primarily utilized in various fields such as databases, caches, distributed systems, and cryptography. It refers to the process of converting an input of any length into a fixed-size string of text, using a mathematical function known as a hash function. The importance of hashing exists in its efficiency and security. For databases and caches, when data is hashed, it allows for quicker data retrieval because it simplifies the search process. For cryptography, hashing ensures security by transforming sensitive information into a format that is not easily decipherable, making it more resistant to hacking. It also helps in data integrity checking by generating checksums. Thus, hashing serves as an essential tool in managing, securing, and speeding up data access in the digital world.


Hashing serves an incredible purpose across various aspects of technology, with its most significant functionality being to facilitate the efficient storage and retrieval of data. This technique, which involves converting input of any size into a fixed size “hash value” or “hash code”, allows us to access data rapidly and efficiently, making it invaluable in database management. Hash values serve as unique identifiers for the corresponding input data, and the data is then stored in a data structure called a hash table. Because hash values are much shorter and simpler than the original input data, it makes navigating a large database significantly quicker and more efficient.In addition, hashing is a fundamental component of data encryption and cybersecurity. In password management, for example, instead of storing the literal passwords, which can easily lead to severe breaches if the database is compromised, the hashed version of the passwords are stored. Whenever a user enters their password, it is hashed using the same hashing algorithm, and the result is compared with the stored hash value to verify password correctness. This method ensures that even if an unauthorized person gains access to the database, they would only see meaningless hash values instead of actual passwords. Hence, hashing is a critical tool in data safety and privacy protection.


1. Password Storage: The most common real world example of hashing is password storage. Most websites and applications that require users to create an account don’t actually store their passwords. Instead, they hash the password and store that hash. Each time the user enters their password, the system hashes the input and compares it to the stored hash. This method means that even if someone gains unauthorized access to the database, they will not be able to use the hashed passwords.2. Blockchain Technology: Another example is the use of hashing in blockchain technology, such as that used in cryptocurrencies like Bitcoin. Each block contains a hash value that represents the contents of the block. If any of the contents are tampered with, the hash value will change and it will immediately indicate that something is wrong. It adds to the security and integrity of the blockchain.3. Digital Signatures: Hashing is also a critical part of digital signature schemes, which are widely used in various data integrity verification and authenticity confirmation processes. When a document is digitally signed, hash technology is used to create a ‘digest’ of the document, which is then encrypted with the signer’s private key. The recipient verifies the authenticity of the document by using the signer’s public key to decrypt the hash and then perform the same hashing function on the received document. If the two hashes match, the document is deemed authentic and unchanged.

Frequently Asked Questions(FAQ)

Q: What is hashing?A: Hashing is a technique used in computing to convert any size of inputs (data, elements, etc.) into a fixed size output using a hash function. It’s commonly used in data structures such as hash tables, digital signatures, and in many other data retrieval applications.Q: What is a hash function?A: A hash function is a special type of function used in computing to map data of any size to a fixed size.Q: What is the output of a hash function called?A: The output of a hash function is typically called a hash code or simply a hash.Q: Why is hashing used?A: Hashing is used to make data retrieval more efficient. By converting the input to a hashed output, it allows data to be indexed in a way that enables faster access.Q: Is a hashed output reversible?A: Generally, a hashed output isn’t meant to be reversible. This characteristic makes hashing an ideal tool for ensuring data security in passwords storing, but depends on the hash function and algorithm used.Q: What is a hash table?A: A hash table is a data structure that uses hashing to store and retrieve data efficiently. It uses a hash function to compute an index into an array where the desired data is stored.Q: How is hashing used in cybersecurity?A: In cybersecurity, hashing is often used to store sensitive data such as passwords securely. Instead of storing the actual password, systems store the hashed output. Q: What is a cryptographic hash function?A: A cryptographic hash function is a special type of security algorithm that takes an input (or ‘message’) and returns a fixed-size string of bytes – typically a cryptographic hash is rendered as a sequence of symbolic or alphanumeric digits.Q: What is a collision in the context of hashing?A: A collision refers to a situation where two different inputs produce the same hash output. One of the goals in designing effective hashing algorithms is to minimize the occurrence of collisions.Q: What does it mean when a hashing algorithm is termed ‘secure’?A: A secure hashing algorithm means that it is computationally impractical to generate the same hash output from two different input values. It also means that it is nearly impossible to regenerate the original input value from the hash value.

Related Tech Terms

  • Collision
  • Cryptographic Hash Function
  • Message Digest
  • SHA (Secure Hash Algorithms)
  • Hash Table

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