I recently created a bunch of Bitcoin addresses (public starting with 1, PK starting with 5) from a paper wallet, that I downloaded from their github (https://github.com/walletgeneratornet/WalletGenerator.net) and ran offline.
I imported the first PK in my full node, it translated to the pub address I expected and I control this address.
I don’t feel comfortable sending coins to addresses I don’t know for sure I control. How can I check securely and “easily” that I control them ? Adding all of those PK in Bitcoin core is long and decreases security.