What is Data Hashing?

Data hashing is a form of encryption using a one-way mathematical function.
When the function is complete, the result is a hash code or value.
The mathematical function used for this conversion is called a hash function.
An important feature of data hashing is that any small change can lead to a large change in the hash value or code.

For example, the folding method of data hashing, which is one of the simplest methods, takes input (e.g., 937482648) and could use a folding function of 3 (i.e. 937 + 482 + 648) to get the hash value. This would give a hash value of 2067.
If the input was a password, when the password is entered, the same function can be performed and if the hash value is 2067, the result is a success.
By hashing a new password input (rather than unhashing the stored value), the security and anonymity of passwords can be maintained.

Why is Data Hashing Important?

• Hashing ensures that when files are downloaded the data has not been altered—if the hashes match, the file is intact and uncorrupted.
• Hashing allows data to be found much faster, since a database can be checked for a short hash value instead of full data.
• Sensitive data (like passwords) can be stored as hashes, meaning even during a breach the attacker cannot access the plain-text data.

Why Learn Data Hashing?

Data hashing is considered one of the basic pillars of computer security.
Understanding hashing is crucial for anyone interested in cybersecurity.
This is especially important as many modern developer and data engineer job interviews require applicants to code or explain data hashing scripts.