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

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

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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.

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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.

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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 -

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

#### Pi in base 26 is equal to

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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. –

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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:

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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."

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

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

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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"?

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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."

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

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

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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).

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

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

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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.

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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.

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