&gt; it&#x27;s discovered to have an incurable security flaw.<p>AFAIK, that&#x27;s not possible. Secure hashing algorithms tend to fracture instead of completely break, so there will be some warning; to change to a new algorithm, simply more than 50% of the Bitcoin miners would have to mine on the chain that relies on that new algorithm, and it thus becomes &quot;voted&quot; in.