자료설명
- 교재의 내용을 바탕으로 과제물에 적합한 형식과 내용으로 정성을 다해 문제를 만들었습니다.
- 교재의 Supplementary Materials를 활용하여 4가지 유형(Listening Comprehension, Gramma, Vocabulary, Reading Comprehension)을 골고루 사용하여 16문제를 정성을 다하여 만들고,
본문/내용
1. Listening Comprehension
1~3) Listen to the following and answer the question.
Pre-history
Prior to the release of bitcoin there were a number of digital cash technologies starting with the issuer based e-cash protocols of David Chaum and Stefan Brands. Adam Back developed hashcash, a proof- of-work scheme for spam control. The first proposals for distributed digital scarcity based cryptocurrencies were Wei Dai’s b-money and Nick Szabo’s bit gold. Hal Finney developed reusable proof of work(RPOW) using hashcash as its proof of work algorithm. In the bit gold proposal which proposed a collectible market based mechanism for inflation control, Nick Szabo also investigated some additional aspects including a Byzantine fault-tolerant agreement protocol based on quorum addresses to store and transfer the chained proof-of-work solutions, which was vulnerable to Sybil attacks, though.
1)Who developed hashcash, a proof-of-work scheme for spam control?
① David Chaum
② Stefan …