Encryption (AQA A-Level Computer Science): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
ShowHide
Practise the questions
10 questions from this quiz
What term describes data that has been encrypted into a scrambled, meaningless format?
What term describes data that has been encrypted into a scrambled, meaningless format?
Ciphertext
In a Caesar cipher with a two-letter shift, which letter would 'A' become?
In a Caesar cipher with a two-letter shift, which letter would 'A' become?
C
Which letter appears most frequently in English text, making it vulnerable to frequency analysis?
Which letter appears most frequently in English text, making it vulnerable to frequency analysis?
e
What is the key difference between substitution and transposition ciphers?
What is the key difference between substitution and transposition ciphers?
Substitution replaces; transposition rearranges
What must happen to the key after encrypting a message with a proper Vernam cipher?
What must happen to the key after encrypting a message with a proper Vernam cipher?
Destroyed after use
In the Vernam cipher XOR operation, when does the output produce a 1?
In the Vernam cipher XOR operation, when does the output produce a 1?
When the two bits are different
What does computational security mean for encryption?
What does computational security mean for encryption?
Secure with current tech in useful time
Why are simple Caesar shift ciphers easy to crack?
Why are simple Caesar shift ciphers easy to crack?
Only 25 possible shifts to try
How does a dictionary attack differ from brute force when cracking encryption?
How does a dictionary attack differ from brute force when cracking encryption?
Dictionary uses common words only
Why are combined transposition and substitution ciphers more secure than either alone?
Why are combined transposition and substitution ciphers more secure than either alone?
Creates two-stage encryption process