INFA 640Cryptology and Data ProtectionPart 1: Hash Codes.
Provide the expected numerical answer along with
your explanation.1-a. A certain communications system uses messages that are 1024 bit long. How many different messages can be supported my such system?
1-b. Often messages are accompanied by hash codes. If the bit length of the hash code is 2 to the sixth power, how many such hash codes can be produced?
1-c. A certain communications system uses messages that are 2 to the tenth power bits long. The accompanying hash code is 64 bits long. How many messages could produce the same hash code?
Part 2. Alpha Encryption.
Provide the answer along with a brief explanation
2-c. An encryption algorithm turned
GOOD MORNING AMERICA
into
FNNC LNQMHMF ZLDQHJZIdentify the encryption algorithm and express it in a mathematical form.
Part 3. PGP Desktop.3-a. In the PGP Desktop encryption system there is (or is not) a green dot under a field labeled
Validity. Describe the significance of that dot.
3-b. In the PGP Desktop, describe the steps necessary to be followed in order to change your
Passphrase.
3-c. The PGP Desktop offers an option called
Free Space Wiping. Describe the action taken, along with the advantages and disadvantages.
Part 4. Number of Keys.
An organization has 20 members. It is desired that each member of the organization be able to communicate securely with any other member, without any other member being able to decrypt their messages.
4-a. How many unique keys are required in a symmetric system?
4-b. How many unique keys would have been required in an asymmetric system?
4-c. What is the meaning of
signinga document? Provide an explanation.
Part 5 Decryption SpeedA certain cryptography vendor was providing an encryption technology that was breakable within
one hour.Considering the continuous increase in computer speed, the company decided to increase the size of the encryption key so that the time to break the encryption become more than 250 hours. What should be the minimum key size increase to meet this objective, considering that in this encryption technology, the increase of a single bit in the size of the encryption key doubles the amount of needed computations.
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Part 7. Encryption
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run rod method, and the rod radius was 0.2654 inches. Decrypt the message and earn (10pts). |
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