1-Both hashing and encryption produce a series of random numbers and letters. Are both concepts the same or different? How are they different in terms of the purposes? Data security involves confidentiality, integrity, authentication, non-repudiation, accountability. How are both techniques to do with these five goals? Why blockhead needs both techniques?

2- Discuss how and why Security, Scalability and Decentralization are three contradictory goals in blockchain world (trilemma)?