-Q. What is Cipher?
Answer: A cipher is an algorithm for performing encryption or decryption. It is a series of steps that can be followed as a procedure.
Q. What is encryption?
Answer: Encryption is a process of converting plaintext into ciphertext using key.
It is a technique of translation of data into a secret code called cipher text.
Q. Using substitution cipher transform the message "HAPPY BIRTHDAY TO YOU" key is 'S'.
Answer:
Q. Using substitution cipher transform the message "HONESTY IS THE BEST POLICY", KEY IS -5.
-Q. What is steganography?
Answer: The word steganography means secret writing. It is the process of concealing a message, file, image , or video within another file in order to hide its existence.
Q. Encrypt following plaintext using transposition cipher.
"The reverse process of transforming ciphertext message back to plaintext message is called decryption " key ZQARXMP.
Q. Encrypt following plaintext using transposition cipher.
key: MAGNETIC
Plaintext: transmit this message
Q. Encrypt following plaintext using transposition cipher.
PLAIN TEXT: "The application layer is the topmost layer in layered network model"
key: MAGABUCK
Q. Encrypt following plaintext using transposition cipher.
-Q. Explain two fundamental cryptographic principles.
Answer: Following the the cryptographic principles:
1) Confidentiality: It is protection of information from unauthorized access. It is done through encryption where plaintext is transformed into cipher text using keys. Secure communication channels use encryption to ensure that only authorized parties can understand the transmitted data.
2) Integrity: Ensure that data remains unaltered during transmission or storage.
Maintained through hash functions, which generate fixed-size hash values for data; any change results in a different hash value.
3) Authentication: Verify the identity of users or systems involved in communication.
It Often involves digital signatures or authentication protocols, using keys, passwords, or biometrics.
Example: Digital signatures confirm that a message was sent by the claimed sender, enhancing trust in the communication process.
Q. What is transposition cipher.
Answer: It is a type of cryptographic algorithm that rearranges the positions of characters in a plaintext message to create ciphertext. They only change the order of characters unlike substitution cipher which replace each letter with another letter.
These are less secure than substitution cipher.
Q. What is cryptography.
Answer: Cryptography is made of greek words which means secret writing. It is a process of encryption and decryption of messages using secret keys.
Q. Define
- Plain text
Answer: The original message, before being transformed is called plain text.
- Cipher text
Answer: After the message is transformed using cryptography, it is called ciphertext. It is made using plaintext and key.
- Encryption
Answer: It is a process which transforms the original message into an unrecognizable or unreadable form. It consists of algorithm or steps that performs various substitutions and transformations on plaintext.
- Decryption
Answer: It is the process of converting encrypted message to its original form. The ciphertext is changed into original plain text.