- C Not A Long Time Ago In A City Far Far Away It Is A Period Of Civil War Some Members Of The Rebellion Hacked And O 1 (144.95 KiB) Viewed 86 times
(C) Not a long time ago in a city far, far away, it is a period of civil war. Some members of the rebellion hacked and obtained personal details about some imperial officers (names, addresses etc). They wrote this information into some cryptocurrency transactions (each transaction typically has some kind of 'note' field that allows arbitrary information to be included, in addition to essential information such as wallet addresses and amount etc; these notes are also included in any relevant blockchain computations), and hence into the blockchain, in the hope that those information can be publicised and never be removed. Explain whether it is possible for anyone to remove such information from the blockchain. Your answer should refer to the relevant cryptographic operations used in cryptocurrencies and their computational difficulty. [5 marks]