# FREE Certified Blockchain Professional (CBCP) Cryptography Questions and Answers

#### The result of multiplying "YES" by "NO" in base 26 is –

Calculate the alphabets using base 26 after converting the letters to their corresponding values.

#### Pick one of the cipher systems listed below that is easiest to decipher using frequency analysis, going from best to worst.

The most resistant to frequency analysis is Random Polyalphabetic, followed by Vignere, Playfair, and Plaintext.

#### A text string is used as a key by _____________ to perform a sequence of shifts on the plain-text.

The Vigenere Cipher uses a text string as a key and a series of shifts on the plain-text to encrypt data. In this case, the sender and the recipient agree on a single key.

#### Divided by (lA2F) base 16, (131B6C3) yields -

The following base-16 division will be used, where A-F stand for 10-15.

#### Pi in base 26 is equal to

Using basic conversions, we convert to 3.1415926 as D.DRS.

#### Divide (HAPPY)26 from (SAD)26 to get the result. We determine the quotient. –

By dividing (HAPPY)26 by (SAD)26, we get KD and MLP as the remainder.

#### The estimated calculations needed to break a six-character password using the 26-letter alphabet are as follows:

The correct response is 26^6 = 308915776.

#### We obtain the following cipher text after encrypting "thepepsiisintherefrigerator" with the Vignere Cipher System and the keyword "HUMOR."

Text of the cipher: Ci = Pi + ki mod m (mod 26).

#### The English language's Index of Coincidence is about

About 0.065 is the IC for the English language.

#### The IC of a symmetric cipher system is 0.041. What is the size of the letter "m"?

We may calculate m using the formula m=5, where m≈0.027n/(I_c (n-1)-0.038n+0.065).

#### We obtain cipher text by encrypting "cryptography" with the Vignere Cipher System and the keyword "LUCKY."

Text cipher: = Ci = Pi + ki mod m (mod 26).

#### The IC is roughly when all letters have an equal chance of being selected.

The IC is around 0.038, which is less than half of the IC for the English language if every letter has the same probability of being chosen.

#### The remaining is equal to (11001001) divided by (100111).

(11001001) divided by (100111) gives us (110).

#### Which letters are used the most frequently in the English language?

These letters' relative frequency, expressed as a percentage, is e-12.702, a-8.167, t-9.056, i-6.996, and o-7.507.

#### In the Playfair cipher, a key table is initially created. The plaintext is encrypted using a key table, which is a 5 by 5 grid of alphabets.

In the Playfair cipher, a key table is initially created. The plaintext is encrypted using a key table, which is a 5 by 5 grid of alphabets. It is required that each of the twenty-five alphabets be distinct, and letter J is left out.

#### The C =(p+3) mod 26 Caesar Cipher is used to encrypt. A case in point is the Caesar Cipher.

Mono-alphabetic ciphers, like the Caesar Cipher, only encrypt or decrypt one alphabet at a time.