In cryptography, the SHA-1 is an encryption hash function that takes an input and generates a 160-bit hash value known as a message summary - usually represented as a 40-digit hexadecimal number.
The SHA-1 algorithm was developed by the NSA, which stands for National Security Agency, in the distant past and is an integral part of Internet exchanges. The SHA-1 algorithm was considered as a secure algorithm for hashing operations. In fact, a hash is a unique string that, based on the input data of a string, creates output as a hash, which must be unique.
For example, when you set a password for your accounts, this password is so-called hashed and stored on the server (although some sites do not believe in this at all!) Now when you want to log in to your account And you enter the password, the password entered by the system is hashed and compared with the hash stored on the server. Simply put, SHA-1 allows you to create a digital signature for a file or any other input value so that anyone who wants to use that file can ensure that the file is genuine and not tampered with.
This number is called a hash value and is used to verify the integrity of the original message. The SHA-1 algorithm is a one-way encryption process, meaning that it is not possible to derive the original message from the hash value. SHA-1 is regarded as secure when used in its intended role, but it has been shown to be vulnerable to certain attack methods. As a result, its use is being phased out in favor of stronger algorithms such as SHA-2.
SHA-1 is widely used as part of the Digital Signature Algorithm in the public key infrastructure to verify that data has not been tampered with or corrupted. It is also used to generate a message authentication code when used in conjunction with a secret key. SHA-1 is considered to be more secure than MD5, although it is not as widely used due to its slower speed. SHA-1 also has vulnerabilities and is being phased out in favor of SHA-2, which is considered to be more secure. SHA-1 is used to ensure data integrity in many areas, including digital certificates, digital signatures, and file integrity. It is also commonly used in password storage and encryption.
The SHA-1 algorithm has drawbacks that make the hash function output not always unique for different values, and for the first time Google was able to create an error in the SHA-1 hash by creating a manipulated PDF type with a specific prefix. . Researchers working on this project were able to hash two different files with this algorithm and the output of SHA-1 was the same for both files!
Google was able to calculate a huge amount of such interference using its cloud infrastructure, and after that, Google predicts that the use of the vulnerable SHA-1 algorithm will decline.
SHA-1 is used in many softwares and protocols today. These include TLS, SSL, PGP, SSH, S / MIME, and IPsec. In these applications, the MD5 integration algorithm can be used, and in the same way, MD4 can be replaced in these applications, which, of course, will guarantee less security. SHA-1 is also used in review control systems such as Git, Mercurial, and Monotone. In these cases, SHA-1 is used to identify and review changes and to detect data corruption or alterations. This algorithm is also used in the Nintendo’s Wii game console to verify a person’s signature when the system boots. But despite all these applications, a potential and organized attack on this algorithm may cause it to break and bypass the system or security service.