1. Bob sends an encrypted message to Alice, and also sends his digital certificate to Alice to prove his identity. How does Alice prove that it is Bob who sent the message?
   • Answer here.
2. The core trust on the Internet is based around PKI (Public Key Infrastructure). Outline how digital certificates are used to provide a degree of trustworthiness.
   • Answer here.
3. Bob has just produced a key pair, in a Base-64 format, and now wants to send this to Alice. What advice would you give him on sending the key pair to Alice?
   • Answer here.

You must understanding how to analyse network traces for tunnels

1. IPSec
   • Steps Here.
2. SSL
   • Steps Here.
3. Client Server Connection on Port 443
   • Steps Here.
4. HTTPs
   • Steps Here.
5. ECDHE
   • Steps Here.
6. SFTP
   • Steps Here.
7. TOR
   • Steps Here.

1. Bob wants to send some Bitcoins to Alice. What are the steps that he will take in order for her to receive them?
   • Answer here.
2. Bitcoin technology has a major problem with its proof-of-work method of gaining a consensus. What are the current drawbacks?
   • Answer here.
3. How does Ethereum overcome the problems of the proof-of-work method?
   • Answer here.
4. How does the payment of gas focus developers to create efficient coding?
   • Answer here.
5. Alice says that her Bitcoin ID address uses Base-64. Is this the case? If not, what format does it use?
   • Answer here.
6. Trent says that no way that anyone can track his transactions on Bitcoin. Is this true? If not, explain your argument.
   • Answer here.
7. What evidence does a miner have to give to show it has found the required hash for a block?
   • Answer here.
8. How many bits does a Bitcoin ID have? Outline the process of generating the ID.
   • Answer here.
9. With Ethereum, with the genesis block, what are the difficulty, the gaslimit and alloc used for?
   • Answer here.
10. Alice tells you that Ethereum uses JavaScript to create a smart contract. You are worried that JavaScript doesn't seem to be a trustworthy language. What is required to make the code running on the blockchain trustworthy?
    • Answer here.
11. Bob generates his private key and views it. Can you explain to him what the following listing defines:
    • Answer here.

1. How do light-weight cryptography methods differ from traditional cryptography methods?
   • Answer here.
2. What are key evaluators that are used to assess light-weight cryptography methods?
   • Answer here.
3. Why would be stream encryption method be preferred to a block encryption method in light-weight cryptography?
   • Answer here.
4. How is the Python yield keyword used in RC4 key stream generation?
   • Answer here.
5. Explain the Fiat-Shamir method protects passwords.
   • Answer here.
6. How does the Pedersen Commitment preserve privacy, and how are they used in cryptocurrency applications?
   • Answer here.
7. How are Range Proofs used to preserve privacy, and how are they used in cryptocurrency applications?
   • Answer here.
8. Bob the Chip Designer wants to use AES for the design of a new RFID tag, but Alice says he should use ChaCha20. Who is right?
   • Answer here.

1. Define the basic security controls using within JWT.
   • Answer here.
2. Bob says that OAuth 2.0 is an excellent way to provide authentication into a corportate infrastructure. Is he correct? Justify your answer.
   • Answer here.