The correct answer is: C. Digital signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit.
Digital signatures are commonly used for software distribution, financial transactions, and other applications where it is important to ensure the integrity and authenticity of a document.
The Information Technology Act, 2000 is an Act of the Parliament of India enacted in 2000. The Act provides for the legal recognition of electronic documents and transactions, and for the establishment of a framework for the use of electronic signatures.
The Act defines an electronic signature as “a subscriber’s authentication of an electronic record by means of a digital signature, electronic authentication code, or any other means of authentication as may be specified by the Central Government in this behalf”.
The Act also provides for the recognition of digital signatures as equivalent to handwritten signatures for the purpose of executing documents and contracts.
Encrypted signatures are a type of digital signature that uses encryption to protect the signature from being tampered with. Encrypted signatures are more secure than traditional digital signatures, but they are also more complex to implement.
Image signatures are a type of digital signature that uses a digital image to represent the signature. Image signatures are less secure than traditional digital signatures, but they are also easier to implement.
Online signatures are a type of digital signature that is created and verified online. Online signatures are convenient and easy to use, but they are not as secure as traditional digital signatures.