Question

Let A’s public key is n=6, 736, 180, 7817, 961, 456, 267 and e = 5 and B sends the ciphertext. c = 456, 871, 122, 391, 882, 538 to A. Determine B’s message in numeric format?

(a) 235813

(b) 57971.89

(c) 770190.04

(d) 687651.9

This question was posed to me by my college director while I was bunking the class.

This interesting question is from Cryptography topic in division Number Theory and Cryptography of Discrete Mathematics

Answer 1

Correct option is (c) 770190.04

The best explanation: It is known that to get original message m after decrypting we can have the formula  m=c1/e. In this case: (456,871,122,391,882,538)^1/3 = 770190.04 and this is the required answer.