Digital Signature Algorithm (DSA) is a signature algorithm, not an encryption algorithm, and uses publickey cryptography to generate digital signatures.
What Is Digital Signature Algorithm (DSA)?
Digital Signature Algorithm (DSA) was proposed by the National Institute of Standards and Technology (NIST). The algorithm is based on the difficulty of computing discrete logarithms.
DSA has three steps:

The first step is to generate a key pair.

The second step is to sign a message.

The third step is to verify the signature of the message.
A digital signature is a mathematical scheme that demonstrates the authenticity of digital messages or documents. A valid digital signature indicates the message was created by a known sender (authentication), and that the message was not altered during its transmission (integrity). Digital signatures are central to modern computer security and commerce.
The DSA algorithm can be used to generate the digital signature of messages. It is normally used in conjunction with other security protocols such as PGP or SSL/TLS. It is also used with some cryptographic nonce schemes and key exchange protocols.
It uses mathematical functions and a set of keys to secure communications over the internet. The private key is used to sign messages and the public key is used to verify that those signatures are authentic. The use of two different keys helps ensure the authenticity of digital signatures.
The DSA algorithm is based on the ElGamal signature scheme, which was developed in 1985, but it has many differences in terms of how it functions and how it secures data. The DSA algorithm requires a random number generator for generating keys and signing data, whereas ElGamal does not. The DSA algorithm also specifies that a message shouldn’t be signed more than once or with different keys, which ElGamal does not specify.
Advantages of Digital Signature Algorithm (DSA)
The digital signature is a process in which the author of the message can verify that the message is not altered after it is signed. The signature also protects the user against forgery.
It uses asymmetric key cryptography. Hence, there won’t be any need for any additional asymmetric key cryptography. This makes DSA faster than other algorithms like RSA.
It requires less memory space than other algorithms because it uses only a 160bit hash value to generate the signature.