It is recommended that you register your work as soon as possible after you have created it. It is also recommended that you register your work prior to publishing, sharing or any private/public exposure. Your rights are strengthened when the time of registration is as close as possible to the time of creation.
Your registration is a Proof of Existence and Proof of Possession. It shows that at the time of registration, the work existed and was in your possession. This can be used to support claims of Copyright authorship and ownership. Furthermore, a third party can independently verify your Copyright registration with just a copy of the file and the Certificate of Registration.
The Blockchain ledger is stored on thousands of computers located all over the world. This ensures that there is no downtime and is virtually impervious to hacking unlike centralized server systems. The cryptographic architecture of the Blockchain engenders trust in the integrity of the data.