Hash is an identifying value that is used to verify the data integrity of messages transmitted over a computer network. The sending computer uses a secret algorithm that computes the value for the message. This value constitutes, in effect, a digital fingerprint for the message because the value is uniquely a product of the message’s content.
Also, the hashing algorithm cannot be derived from the message content or value. The message and the value are then transmitted. The receiving computer, which also knows the secret algorithm, performs the same computation on the message. If the resulting value does not agree with the value received from the sending computer, then it is proved that the message was altered en-route, and the message is discarded. See one-way function.
Technipages Explains Hash
A hash is a function that is used to convert a data value to a much smaller value. A hash is a function that is used to map an original data of a big size onto a data of a smaller size, a hash masks an original data with another value. Based on this, a hash consumes lesser space. Hashing indexes a data and when a hash function is carried out on a piece of data, locating the data would become easy as the value of the data would be found. Hash functions are one way; they cannot be reversed.
Hashed values are smaller than their originals, an application of these can be seen in the compression of data’s like media files wherein the size of a media file is reduced. Hashing can also be used to retrieve data and confirm the validity of a data.
The values gotten from a hash function is to be stored in a hash table, the table ascribes a unique value to a data, so when the original data is being sourced for, the hash is decoded, and a value is generated. Hashing of data is a common practice in computer science, and it is used for several different purposes.
Common Uses of Hash
- The underlying technology for a Hash is the underlying technology for compression software which reduces the size of media files
- A hash is a sure way to ensure the safe transfer of data without the data being altered or lost
- Retrieval and revalidation of a data is possible with the presence of a hash
Common Misuses of Hash
- A hash does not mask a data’s value to be able to locate the data later on
- Once a hash operation has been carried out, it can be reversed.
