UGC NET Questions (Paper – 1)

Statements A, B and C accurately summarise core ideas of cryptography, encryption and decryption. They show how information is transformed and restored using algorithms and keys. Statement D is dangerously false because private keys must be kept secret; sharing them openly destroys security. Thus, the correct answer is the combination A, B and C only.

Option A:
Option A is incorrect because it lists only A and B as correct, leaving out C. Statement C is also correct, since decryption reverses encryption to recover plaintext. Excluding C gives an incomplete picture of the cryptographic process.

Option B:
Option B is incorrect because it groups A, C and D as correct, thereby accepting D. Statement D contradicts the requirement to keep private keys secret and would compromise secure communication.

Option C:
Option C is correct because it recognises that protecting, encrypting and decrypting data are the three linked components specified in A, B and C. It excludes the unsafe recommendation in D.

Option D:
Option D is incorrect because it includes B, C and D only, omitting A and accepting D. This both weakens the conceptual definition and endorses insecure behaviour.

Encryption converts plaintext into ciphertext using an algorithm and key so that only authorised parties can recover the original information. It safeguards confidentiality when data is stored or transmitted over insecure networks. Modern ICT systems rely heavily on encryption for secure web browsing, email and payment transactions. Therefore the process described is encryption.

Option A:
Option A, compression, reduces the size of data to save bandwidth or storage but does not by itself prevent unauthorised reading. Compressed data is usually easily decompressed without secret keys.

Option B:
Option B, virtualization, refers to creating virtual instances of hardware or operating systems and is unrelated to coding data for secrecy. It addresses resource utilisation rather than confidentiality.

Option C:
Option C is correct because encryption specifically targets security by scrambling data based on cryptographic techniques. Without the appropriate decryption key, intercepted ciphertext should be unintelligible to attackers.

Option D:
Option D, defragmentation, reorganises files on storage media to improve access speed and has no role in preventing others from understanding the content.

Encryption transforms plain text into cipher text using algorithms and keys, protecting the confidentiality of information during storage or transmission. Only parties possessing the correct key can reverse the process through decryption. This practice is fundamental to secure communication over public networks. Consequently, the process described is encryption.

Option A:
Option A, decryption, is the reverse operation that converts cipher text back into readable form and does not describe the initial protection step.

Option B:
Option B is correct because encryption is defined as the act of encoding information so that only authorised users can access its content, matching the description in the question.

Option C:
Option C, compression, reduces file size to save space or bandwidth but does not prevent unauthorised reading.

Option D:
Option D, authentication, confirms the identity of users but does not itself convert data into unreadable form.

Decryption applies a cryptographic key and algorithm to ciphertext to retrieve the original plaintext. It is the necessary counterpart of encryption in secure communication systems. Without decryption, authorised users could not read protected information. Thus, the process is called decryption.

Option A:
Option A is correct because decryption precisely denotes reversing encryption to recover the original data.

Option B:
Option B, encryption, is the forward process of encoding data and does not describe restoration to readable form.

Option C:
Option C, hashing, produces fixed length digests for integrity checking but is generally one way and not used to recover original data.

Option D:
Option D, scanning, may refer to searching or virus checking and is not related to cryptographic reversal.

Encryption transforms plaintext into ciphertext using algorithms and secret keys, protecting information from unauthorised access during storage or transmission. It is fundamental to secure communication over networks. Only those with the correct key can restore the original data. Therefore, the security process described is encryption.

Option A:
Option A is correct because encryption is defined as the process of encoding data to maintain confidentiality and integrity.

Option B:
Option B, decryption, is the reverse process that converts ciphertext back to plaintext and does not match the direction described.

Option C:
Option C, compression, reduces file size but does not by itself secure data.

Option D:
Option D, routing, directs network packets to their destination and is unrelated to transforming data for secrecy.

Encryption uses mathematical algorithms to transform plaintext into ciphertext that appears meaningless without the correct key. This protects the confidentiality of sensitive data as it travels over networks or resides on storage devices. Even if attackers intercept the data, they cannot easily interpret it without decryption keys. Thus, the protective process described in the stem is encryption.

Option A:
Option A, compression, reduces the size of data for efficient storage or transmission but does not intentionally hide the content from unauthorised viewers.

Option B:
Option B is correct because encryption is explicitly defined as encoding information to prevent unauthorised disclosure and is a cornerstone of contemporary ICT security practices.

Option C:
Option C, formatting, prepares storage media or arranges document appearance and does not inherently provide confidentiality.

Option D:
Option D, duplication, involves making copies of data, which can actually increase exposure rather than protect against access.

Encryption is a cryptographic process that transforms plaintext into ciphertext using an algorithm and key. The goal is to protect the confidentiality of information during storage or transmission. Only entities possessing the correct decryption key can restore the original content. Thus, the central purpose of encryption is controlled access, not visual enhancement or deletion.

Option A:
This option incorrectly associates encryption with improving colour resolution, which relates to multimedia quality rather than security. Encryption does not change the visual properties of images in a meaningful, viewable way. Hence, the statement misunderstands the concept.

Option B:
This option correctly notes that encryption makes data unintelligible to unauthorised observers. It ensures that intercepted messages cannot be easily understood, thereby safeguarding sensitive information. Decryption reverses the process for authorised users, fulfilling the core security objective.

Option C:
Deleting files removes them from storage, which is a data sanitisation activity. Encryption, however, preserves data while restricting its readability. Therefore, equating encryption with deletion is inaccurate.

Option D:
Aesthetic design of interfaces is a usability and design concern, not a security function. While encrypted systems may have modern interfaces, the encryption process itself does not improve visual design.

Statements A, B and D correctly describe how digital signatures work in secure ICT systems. They rely on cryptographic methods, maintain integrity and are commonly implemented through PKI frameworks. Statement C is false because merely scanning a handwritten signature does not provide cryptographic security or tamper detection. Hence, the correct combination is A, B and D only.

Option A:
Option A is incorrect because it lists only A and B as correct, omitting D. While A and B are true, statement D is also important in explaining typical infrastructure used for digital signatures. Leaving out D makes the answer technically incomplete.

Option B:
Option B is correct because it includes all three accurate statements about digital signatures. It excludes the superficial notion in C that an image scan can substitute for cryptographic signing. This reflects proper understanding of secure digital authentication.

Option C:
Option C is incorrect because it groups B and D only and omits A. Statement A is essential in defining digital signatures as cryptographic constructs. Without it, the conceptual explanation is weakened.

Option D:
Option D is incorrect because it includes A, C and D as correct statements. Accepting C would mean treating non-cryptographic image scans as equivalent to digital signatures, which is not correct.