The genealogy analogy

One of the authors recently attended a Chinese university alma mater reunion event in Beijing, where blockchain became a hot discussion topic. A very well-regarded schoolmate and scholar, Professor Yang, who has authored books on cryptography and public data safeguards, used genealogy to describe a blockchain. This is a well-thought-out analogy since it explains blockchain intuitively and easily. The analogy is borrowed here to illustrate the basic ideas behind the technology. 

Back in the old days in China, it was a custom for each family of a clan (sharing the same last name) to keep a copy of the genealogical tree of the clan. When members of a family changed due to either marriage or the birth of an offspring, as well as adoption, the new member's name would appear in each copy. However, the new member had to be accepted by the clan before the name could be added in. There were cases when a marriage was not endorsed by a majority of the clan due to various reasons...