For the introduction, read part 5 A here.
Some people might think “So what, I will make sure my coins are in a quantum resistant address after the upgrade. So I won’t run any extra risk.” This, however is not true. The fact that not 100% of the circulating supply is protected, does bring a risk for the value of all 100%. So each coin, the ones in quantum resistant addresses and the ones in old addresses. You need to guarantee there will not be a news headline screaming “BTC hacked!” (Or whatever other blockchain project) which is the nightmare of any investor. Reading or hearing that, means sell your bags, even if you yourself use the quantum resistant option. Having your personal BTC protected, simply means that the amount of BTC will be safe, not the value of your BTC. So in the case where someone’s BTC gets stolen, you yourself will still have 3 BTC. But because of the news, which will cause people to sell and the BTC value to drop, your 3 BTC that used to be worth 40.000$, now is worth 3.000$ for example, while the value still drops. The bigger the percentage of coins on an old vulnerable address, the bigger the security risk. The MtGox hack of 2011 caused an imediate drop of 49% and a 5 months drop of 93%. That was 2k stolen BTC (0.04% circ suppl back then) hacked from an exchange. Not BTC itself. In this case it will be the blockchain that is hacked. That is a next level hack compared to exchange hacks we eventually got used to now. So to make the upgrade to a success, all coins need to be moved from old addresses to new quantum resistant addresses. This means that for you as a user, to secure your value, you depend on the action of all other users. Which is at this point of time estimated to be around 7 million users. Which includes about 700.000 addresses that hold more than 1 Bitcoin. That is a lot of people that need to take action. Security wise, you depend on the need for all those other other people to pay attention to developments, understand the necessity, understand the need for personal action after BTC itself has already upgraded to quantum resistance, behave responsible, proactive and fast. This is the human factor.
In cryptocurrency, being a quantum resistant blockchain isn’t about offering the option. It’s about protecting your currency and the value of that currency. So either you have a 100% quantum resistant blockchain that protects all of it’s supply, or a certain percentage is obviously still vulnerable to hacks.
You can continue reading part 5 C here: the hard to solve issue of lost addresses