## Network Security and Cryptography (CSN09112)[Back] This outlines Test 1 which is taken on ## Background**Ciphers and Fundamentals**[Link]**Symmetric Encryption**[Link]**Hashing**[Link]**Public key**[Link]**Key Exchange**[Link]**Digital Certificates**[Link]
## Test 1 (Challenges)- 1. Hex Code Challenge [ Try].
- 2. Pigpen [ Try].
- 3. Polybius [ Try].
- 4. Morse [ Try].
- 5. ADFGVX [ Try].
- 6. Scrambled Alphabet [ Try]. Can you beat 5 minutes?
## Test 1 (Examples)## Test 1 (Some principles)- 1. Key Enthropy [ Try]. How many bits can represent X phases? Just take the Log(X), and divide by Log (2).
- 2. John the Ripper, Hashcat and Ophcrack: Here
- 3. Using OpenSSL to salt passwords: Here
- The table you will use in the test is: Here and you can use a calculator.
## Study QuestionsTry to review your knowledge by answering these questions: - Can you convert characters from one format to another, such as in binary, hex, ASCII and Base-64 (remember: hex uses four bits at a time, and Base-64 uses six bits at a time)?
- Do you know the basic theory of converting a bit stream into Base-64 (remember 6 bits at a time and convert from table)?
- Do you understand how to use some key ciphers, including shifted alphabet, scrambled alphabet, Vigenere, Pigpen and rail codes?
- Can you do a simple Diffie-Hellman calculation and end up with the same shared key?
- Do you understand how the number of keys relate to the security of the ciphers?
- Can you work out key enthropy, so that if you have 2,048 phases, you can calculate that this is equivalent to 11 bits [log(2048)/log(2)]?
- Would you know how long it would take to crack a code next year, if it takes 10 years now, and computing power doubles each year?
- Do you understand how public and private key encryption is used, along with the usage of digital certificates?
- Do you understand the conversion of passwords into hashed passwords, and use tools such as John The Ripper, Hashcat, Ophcrack and OpenSSL?
## TestsHere are some sample tests: ## Test detailsYou will answer the questions with either fixed answers, short explainations or with multiple choice. Time for test: 1 hour 15 minutes Possible study areas: - Solve ASCII hexadecimal encoding.
- Solve ASCII binary encoding.
- Solve Morse encoding.
- Solve the shifted alphabet code.
- Create the Vigenere Code for a given plain text string and key.
- Able to convert bit streams to hexadecimal.
- Able to convert binary streams to Base 64.
- Solve Playfair codes.
- Solve Rail codes.
- Solve scrambled alphabet code.
- Calculate the entropy of passwords.
- Calculate simple Diffie-Hellman.
- Determine time to crack a code, on average, given time to test key.
- Determine time to crack a code, for increasing computing power.
- Understands how public key encrypts data.
- Understands how public key is used to provide identity.
- Understands the key elements of a digital certificate.
- Understand the processing of salting a password and its usage in encryption.
- Password hash cracking/salting (LMHASH/MD5).
Tables given are ASCII table, Morse and Base 64. ## What about I know from a practical point-of-view?The two main labs you should know about are here: |