Q. Choose from among the following cipher systems, from best to the worst, with respect to ease of decryption using frequency analysis.

View solution

Q. On Encrypting “thepepsiisintherefrigerator” using Vignere Cipher System using the keyword “HUMOR” we get cipher text-

View solution

Q. On Encrypting “cryptography” using Vignere Cipher System using the keyword “LUCKY” we get cipher text

View solution

Q. The Index of Coincidence for English language is approximately

View solution

Q. If all letters have the same chance of being chosen, the IC is approximately

View solution

Q. Consider the cipher text message with relative frequencies:

4 0 10 25 5 32 24 15 6 11 5 5 1 2 6 6 15 19 10 0 6 28 8 2 3 2
The Index of Coincidence is

View solution

Q. Consider the cipher text message:

YJIHX RVHKK KSKHK IQQEV IFLRK QUZVA EVFYZ RVFBX UKGBP KYVVB QTAJK TGBQO ISGHU CWIKX QUXIH DUGIU LMWKG CHXJV WEKIH HEHGR EXXSF DMIIL UPSLW UPSLW AJKTR WTOWP IVXBW NPTGW EKBYU SBQWS

Relative Frequencies –
3 7 2 2 5 5 7 9 11 4 14 4 2 1 3 4 6 5 6 5 7 10 9 8 4 2

The Index of Coincidence is –

View solution

Q. A symmetric cipher system has an IC of 0.041. What is the length of the key ‘m’?

View solution

Q. In public key cryptosystem _____ keys are used for encryption and decryption.

View solution

Q. In public key cryptosystem which is kept as public?

View solution

Q. In a trapdoor function, the functions are easy to go in

View solution

Q. Pretty good privacy program is used for

View solution

Q. PGP system uses

View solution

Q. Private key algorithm is used for _____ encryption and public key algorithm is used for _____ encryption.

View solution

Q. Which are called the block ciphers?

View solution

Q. Which has a key length of 128 bits?

View solution

Q. Which algorithm can be used to sign a message?

View solution

Q. Examples of hash functions are

View solution

Q. A cryptographic hash function has variable output length.

View solution

Q. A set of numbers is called as super increasing if

View solution