Classical Encryption Techniques: Transformation of Plain Text into the Encoded Format i,e; Cipher Text

In brute force attack, on average half of all possible keys must be tried to achieve success.

If the sender and receiver use different keys, the system is referred to as conventional cipher system.

Divide (HAPPY)26 by (SAD)26. We get quotient –

An encryption scheme is unconditionally secure if the ciphertext generated does not contain enough information to determine uniquely the corresponding plaintext, no matter how much cipher text is available.

Dividing (11001001) by (100111) gives remainder –

The time required to convert a k-bit integer to its representation in the base 10 in terms of big-O notation is

In base 26, multiplication of YES by NO gives –

Division of (131B6C3) base 16 by (lA2F) base 16 yeilds –

The estimated computations required to crack a password of 6 characters from the 26 letter alphabet is-

Monoalphabetic ciphers are stronger than Polyalphabetic ciphers because frequency analysis is tougher on the former.

Which are the most frequently found letters in the English language ?

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

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

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

Pi in terms of base 26 is: