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Hashing: How Does It Enhance Data Security?

Hashing: How Does It Enhance Data Security?

 By Charles Joseph | Cybersecurity Researcher
 Published on August 1st, 2023
This post was updated on November 25th, 2023

Hashing is a method used to convert any type and size of data into a fixed-length string of characters or numbers. It is a one-way function, meaning once the data has been transformed into a hash, it cannot be converted back to its original form. The key aspect is that even a minor change in the input data produces a significant change in the hash output, enhancing the security and integrity of the hashed data.

Hashing Examples

1. Password Storage

One of the quintessential examples of hashing in everyday life is password storage. Instead of storing the actual passwords that users create, systems often store the hash values of these passwords. The mechanism behind this process is reasonably straightforward and clever in its simplicity.

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When you set up a password for a new account, the system creates a hash of that password and stores this hashed value. Importantly, the original password isn’t kept anywhere in the system. This means that even if a malicious party were to gain access to the system’s stored data, they wouldn’t find the real passwords, just hashed strings that wouldn’t make sense or be of much use without the original input.

Each time you return to the site and enter your password into the login screen, the system generates a new hash from the password you’ve entered. This newly created hash is then cross-referenced with the stored hash associated with your account. If the generated hash and the stored hash match, this means you’ve entered the correct password and you’re granted access to your account. As you can see, hashing plays a crucial part in maintaining the security and privacy of your online accounts.

2. File Integrity Checks

Another simple, yet potent example of hashing is employed in file integrity checks. This is particularly valuable when downloading large or vital files from the internet where the risk of corruption or tampering during the transfer process is present.

To ensure that your download is both complete and undisturbed, the publisher usually provides a hash value for the file. This hash value is generated from the original file before it is made available for download. It acts as a digital fingerprint of the file – a unique identifier.

Upon completing the download on your end, you can generate a hash of the downloaded file using the same hash function that the publisher used. By comparing this newly-generated hash with the one provided by the publisher, you can verify the integrity of the file. If the hash values match, it confirms that the file you downloaded is exactly as intended, with no missing pieces or unwanted alterations.

Hashing, as used in file integrity checks, therefore provides a peace-of-mind solution to validate the integrity of data and prevent unnoticed corruption or unintended tampering.

3. Blockchain Technology

Perhaps one of the best-known applications of hashing in recent years can be found in blockchain technology. This innovative technology underpins digital currencies like Bitcoin and Ethereum, among others, and provides a high level of security and transparency.

In a blockchain, every transaction is hashed and those hashes are stored in a sort of database known as a block. However, it doesn’t stop there. Each block in the chain includes the hash of the previous block, linking them all together in chronological order.

The inclusion of the previous block’s hash is a critical part of blockchain security. This chain of hashes means that, if someone attempts to alter a transaction after it has been recorded, not only would the hash of the transaction change, but so would the hash of each following block. Given the computational impracticality of regenerating these hashes, it provides a powerful deterrent against tampering.

Consequently, hashing’s role in blockchain technology is foundational. It is what assures the trustworthiness of transactions, affirming their integrity and resistance to alteration or deletion – the very pillars on which blockchain stands.


Thus, hashing is a crucial component in many facets of digital life, providing security, integrity, and functionality in areas ranging from password storage to blockchain technology. Its ability to translate any form of data into a unique, indecipherable string makes it an invaluable tool for ensuring data integrity and security in an increasingly digitized world.

Key Takeaways

  • Hashing is a method that transforms any data type into a unique string of characters, enforcing data security and integrity.
  • Hashing is used in password storage where the password is hashed and protected, preventing malicious parties from seeing the original password.
  • File integrity checks use hashing to confirm that a downloaded file is complete and hasn’t been tampered with.
  • Blockchain technology uses hashing to link transactions together securely, ensuring the data integrity of each transaction.
  • The unique basis of hashing means that even a minor change in input data will result in a major change in the hash result, adding another layer of security.

Related Questions

1. What is a hash function?

A hash function is a specific computation that is used to map data of arbitrary size (input) to fixed-size values (output). The outcome, known as the hash result, is typically a string of numbers and letters.

2. Is it possible to decode a hash back to its original data?

No, it’s not feasible. Hashing is a one-way function. Once the data is transformed into a hash, it can’t be reverted back to its original form.

3. Why is each blockchain transaction hash unique?

Each transaction includes unique elements (such as the transaction details, timestamp, and more) that, when hashed, create a unique outcome. No two transactions will have the same hash.

4. How does hashing benefit password storage?

Hashing enhances password protection by ensuring the original password isn’t stored anywhere within the system. Instead, only the hash of the password is stored, making it difficult for potential intruders to decode.

5. Can two different inputs create the same hash output?

It’s extremely unlikely but not impossible. This is known as a hash collision. However, the chances of it happening are so low in a well-designed hash function that it’s generally not a concern.

"Amateurs hack systems, professionals hack people."
-- Bruce Schneier, a renown computer security professional
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