Is there a secure method to block ads within Safari? In order to block ads, most ad blockers require that they can see and change your encrypted traffic. This means that they would be able to see things like bank passwords transfer in clear text. My understanding is that on mobile Safari, ad blockers are not allowed to connect to the internet and simply block certain connections. Is there something similar on Safari for Mac where there is no way you could read and record private traffic?
Safari’s content blocking functionality provides an API for third-party apps to provide block lists.
Apps tell Safari in advance what kinds of content to block. Because Safari doesn't have to consult with the app during loading, and because Xcode compiles content blockers into bytecode, this model runs efficiently. Additionally, content blockers have no knowledge of users' history or the websites they visit.
My favourite app that implements content blockers is AdGuard for Safari as it is open source, lightweight and very effective in blocking with easy customisation to add your own rules (no affiliation).