- 2023 Sep 04
In today’s world, where internet communications have become widespread, the need for protecting sensitive information and ensuring trust in communications is crucial. One of the fundamental methods for information protection is the use of encryption algorithms. One popular encryption algorithm is SHA-256.
What is SHA-256 algorithm?
SHA-256 (Secure Hash Algorithm 256-bit) is one of the hash algorithms used to generate a 256-bit (32-byte) hash value from input data. This algorithm is defined by the National Institute of Standards and Technology (NIST) in the United States and is widely used in information security and cryptographic applications. The hash value generated by the SHA-256 algorithm is a unique 256-bit binary string that is produced for a specific input. This characteristic means that even a slight change in the input will result in a significantly different final hash value.
SHA-256 algorithm features
–Fixed-length output: SHA-256 generates a hash value with a fixed length of 256 bits (32 bytes).
–Resistance to Randomization: Even with a small change in the input, the output changes completely, and this property is called resistance to randomization.
–One-wayness: It is not possible to reconstruct the original input from a specific output by generating a hash. In other words, it is not possible to access the original input by using a hash.
–Security: SHA-256 provides a high level of security and is resistant to various attacks aimed at altering the output or retrieving the main input.
–Fast Execution Capability: The SHA-256 algorithm is generally executed at high speed and is capable of processing large amounts of data quickly.
–Wide Usage: SHA-256 is used in many fields including information security, digital signatures, proof of authenticity, and identity verification.
–International Standard: SHA-256 is an international standard established by the National Institute of Standards and Technology (NIST) in the United States. It is used in many systems and security protocols.
The application of the SHА-256 algorithm (Secure Hash Algorithm 256-bit)
SHA-256 Encryption and Digital Signature: Using SHA-256, a hash can be generated from input data, and then a digital signature can be created on the hash using a private key. This application is crucial for the security of internet communications, file signatures, and detecting unauthorized changes in critical information.
Security of SHA-256 Encryption Systems: This algorithm provides the ability to authenticate information and ensure security in encryption systems as a secure hash function.
Information Security and Privacy: In the field of personal information security and privacy, SHA-256 is used. For example, in identity verification systems, encryption of user data, and generating password hashes, SHA-256 is utilized. This algorithm enhances the security of personal information and prevents unauthorized access to it.
Blockchain Security and Cryptocurrencies: In blockchain technology and cryptocurrencies like Bitcoin, SHA-256 is used as a hashing algorithm. This algorithm is used to create digital signatures in blockchain transactions and ensures the security and integrity of information.
Web Security: SHA-256 is used in many web security protocols and standards. For example, in the HTTPS protocol, SHA-256 is used to create digital signatures on SSL/TLS certificates.
SHА-256: A hash function
SHA-256 is a hash function that converts its input into a unique hash value with a fixed length. This algorithm is composed of various stages that are applied iteratively to produce the final output. These stages include.
Preprocessing: The input message is divided into blocks of 512 bits. If the length of the message is not a multiple of 512 bits, additional blocks are filled with zeros. Additionally, the length of the message (in bytes) is appended to the first block as a 64-bit number.
Message Schedule:For each input block, 64 32-bit words are generated. These words are calculated based on previous values and specific functions.
Main Rounds:Intermediate hashes are updated using logical and abstract functions. Each block of input is combined with the previous input and the derived words obtained in the previous stage.
Hash Generation:After performing the main steps on all input blocks, the final result is generated as the output of the algorithm. This output is a 256-bit hash value, which is typically represented as either a numerical value or a string of hexadecimal numbers from 0 to F.
Hash algorithms with higher security than SHA-256
-SHA-3 is a new standard from the SHA algorithm family defined by NIST. SHA-3 utilizes the Keccak hash function and comes in three versions with hash lengths of 224, 256, and 512 bits. This algorithm has been introduced as a replacement for SHA-2 and in some cases provides higher security compared to SHA-2.
-BLAKE2 is a fast and secure hash algorithm that has been developed as an extension of the BLAKE algorithms. BLAKE2 supports different hash lengths, including 256 and 512 bits. Some of its advantages include high speed, strong security, and resistance against collision attacks.
-Whirlpool is a secure and powerful hash algorithm. This algorithm utilizes a hash length of 512 bits and, in some cases, provides higher security compared to SHA-2 algorithms. As technology and security standards continue to evolve and update, it is possible that newer hash algorithms with even higher security may be introduced in the future.