UGC NET Questions (Paper – 1)

Statements A, B and D correctly describe digital signatures, while C confuses them with mere images. Digital signatures rely on cryptographic keys to verify both the sender and the integrity of the document. They are widely used in e-governance workflows to legally sign electronic forms. Graphical images of signatures do not provide cryptographic security, so C must be excluded from the correct set.

Option A:
Option A is correct because it includes A, B and D, which all reflect authentic properties and uses of digital signatures. It properly leaves out C, which treats digital signatures as simple pictures with no cryptographic basis. This option therefore matches the technological and legal understanding of digital signatures.

Option B:
Option B is incomplete because it selects only A and B and omits D. While A and B are true, ignoring the practical use of digital signatures in e-governance systems underestimates their institutional role. Since D is also correct, this combination does not list all the true statements.

Option C:
Option C is wrong because it combines B, which is true, with C, which is false. C equates digital signatures with pasted images, ignoring the essential role of cryptographic algorithms and keys. Any option that includes this misunderstanding cannot be accepted as correct.

Option D:
Option D is incorrect because it assumes that all four statements are correct and thus accepts C. Since C misrepresents digital signatures as non-cryptographic images, the presence of C makes this combination invalid.

A digital signature uses asymmetric cryptography to bind a person's identity to a digital document through a unique key pair. Verification processes confirm that the document originated from the claimed sender and has not been altered in transit. In many countries, digital signatures have legal validity for e-governance and e-commerce transactions. Hence, the cryptographic authentication method described is a digital signature.

Option A:
Option A, digital watermark, embeds information into media for ownership identification but does not necessarily authenticate the sender in formal transactions.

Option B:
Option B is correct because ICT security frameworks explicitly define digital signatures as providing authenticity, integrity and non-repudiation, aligning with the functions listed in the stem.

Option C:
Option C, simple password, offers only basic authentication and does not involve cryptographic binding of identity to a specific document.

Option D:
Option D, captcha code, distinguishes human users from automated bots but does not certify document origin or integrity.

A digital signature uses algorithms and keys to bind the identity of a signer to a digital document in a way that tampering can be detected. It is legally recognised in many jurisdictions and supports secure e governance and e commerce. Unlike a mere image of a handwritten name, a digital signature has cryptographic strength. Thus, the method described is a digital signature.

Option A:
Option A is correct because digital signature is the standard term for cryptographically generated signatures used in secure electronic transactions.

Option B:
Option B, manual, signature refers to handwritten marks on paper and does not inherently support electronic verification or integrity checks.

Option C:
Option C, scanned, signature is just a picture of a manual signature and can be copied or altered without cryptographic safeguards.

Option D:
Option D, symbolic, signature is not a formal category in information security and could refer to any representation, lacking precise meaning.

Digital signatures are generated using a sender’s private key and verified using the corresponding public key. If verification succeeds, the recipient gains assurance about who signed the document and that its contents have not changed since signing. This supports authentication, integrity and often non-repudiation in electronic transactions. Therefore, the primary function of a digital signature is to provide trustworthy identity and content assurance.

Option A:
Decorative graphics may look like signatures but can easily be copied and do not provide any cryptographic proof of origin or integrity. They are purely visual.

Option B:
Physical ink signatures apply to paper documents and are not equivalent to digital signatures in ICT systems. They do not rely on cryptographic keys or electronic verification.

Option C:
This option correctly explains that a digital signature is based on public-key cryptography and is used to authenticate the sender and detect any alteration of the document, providing integrity and non-repudiation in electronic exchanges.

Option D:
A tool that prevents a document from ever being opened would defeat the purpose of communication and is not what digital signatures do. Signatures verify authenticity and integrity; they do not block access to the document.