The cryptographic technique used to verify data integrity is hashing.
Hashing is a one-way function that converts any data into a unique, fixed-length string of characters called a hash. This hash acts like a fingerprint for the data, ensuring that any changes to the original data will result in a different hash.
Here's how it works:
* **Data input:** The original data is fed into the hashing algorithm.
* **Hash generation:** The algorithm processes the data and produces a unique hash value.
* **Comparison:** If the hash value of the original data matches the hash value of the received data, it confirms that the data has not been tampered with.Hashing is widely used in various applications, including:
* **Password storage:** Instead of storing passwords directly, websites store their hashes, protecting them from unauthorized access.
* **Digital signatures:** Hashing ensures the authenticity and integrity of digital documents.
* **File integrity checking:** Hashing verifies that downloaded files have not been altered during transmission.Common hashing algorithms include:
* **MD5** (Message Digest 5)
* **SHA-1** (Secure Hash Algorithm 1)
* **SHA-256** (Secure Hash Algorithm 256)While hashing is a powerful tool for verifying data integrity, it's important to note that it does not guarantee confidentiality. Hashing does not encrypt the data, so anyone with access to the hash can still see the original data if they have it.
