You can read part 1 here, and part 2 here, and part 3A here, and part 3B here, and part 3C here, and part 4A here, and part 4B here, and part 4C here, and part 4D here
For the introduction, read part 5 A here, part 5 B here and part 5 C here
The time factor
The longer implementation is postponed, the bigger the risk that another factor will become a problem: time. As said before, the implementation is a specialism, it takes time to figure out what to implement and how, it’s no small adjustment, it affects several components of the blockchain, it affects exchanges, ledger, supporting systems and then consensus takes time, migration takes time if completion is possible at all. A timeline assessment needs to be made for all consecutive events. The events will follow each other, they can’t be taken care of all at the same time. There can’t be consensus on a method that hasn’t been proposed yet. You can’t propose a method without having decided which method you want to use. Exchanges will not start to adapt without the assurance that consensus is reached and the changes will actually apply to the blockchain. Etc. etc. All these events have a timeline and will follow each other up: The research period, decision period, development and implementation period, adjustment period for supporting systems, consensus period, exchange adoption period, migration period. All these consecutive events take time. To make a serious risk assessment, this timeline needs to be made. Then estimates need to be made on quantum computer and quantum algorithm development and the expected timeline. And on top of that, you need to take into account that at a certain point of time post-quantum cryptographers will be quite busy due to the fact that there will be a domino effect that causes a growing group of companies, blockchain and other companies, to start changing signature schemes. Lots of projects and companies are postponing, until the masses start to move. Cryptographers will become scarce and expensive. So for some projects the knowledge might not be easily available to figure things out.
You can continue reading part 5 E here: Black swan event