What is SHA1?
SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function that was developed by the National Security Agency
(NSA) in the early 1990s. It is a 160-bit hash function that takes an input (or 'message') and returns a fixed-size
output, which is a 'message digest'. The output, or message digest, is a unique representation of the input, and any
change made to the input will result in a different output.
SHA-1 is widely used in various applications such as digital signature, password hashing, and data integrity. It is
also used in many security protocols and standards, such as SSL/TLS (Secure Socket Layer/Transport Layer Security)
and PGP (Pretty Good Privacy).
However, SHA-1 has been found to be vulnerable to collision attacks, which means that it is possible for attackers to
create two different inputs that produce the same hash output. This can lead to security issues, such as the ability
to forge digital signatures or impersonate other parties. Because of this, SHA-1 is now considered to be a weak
hashing algorithm and should be avoided in new systems. It is recommended to use stronger hash functions such as
SHA-256, SHA-3.