symetric cipher

Objective:

• Present an overview of the main concepts of symmetric cryptography.
• Explain the difference between cryptanalysis and brute-force attack.
• Summarize the functionality of DES.
• Present an overview of AES.
• Explain the concepts of randomness and unpredictability with respect to random numbers.
• Understand the differences among true random number generators, pseudorandom number generators, and pseudorandom functions.
• Present an overview of stream ciphers and RC4.
• Compare and contrast ECB, CBC, CFB, and counter modes of operation.
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• Assignment
• 2.1 What are the essential ingredients of a symmetric cipher?
• 2.2 What are the two basic functions used in encryption algorithms?
• 2.3 How many keys are required for two people to communicate via a symmetric cipher?
• 2.4 What is the difference between a block cipher and a stream cipher?
• 2.5 What are the two general approaches to attacking a cipher?
• 2.6 Why do some block cipher modes of operation only use encryption while others use both encryption and decryption?
• 2.7 What is triple encryption?
• 2.8 Why is the middle portion of 3DES a decryption rather than an encryption?
• Complete your answers on a WORD Document.