It does not look like encryption is even stated on their homepage.

1: bkmker is encrypted. Think 1pass but for bookmarks.

2: This is not a browser bookmark syncing tool. Its a stand alone bookmarking tool and website, it does not share your bookmarks with the browser. You can review the bookmarks from any browser.

3: Zero knowledge privacy. The only data bkmker knows about your bookmarks is the opaque binary produced from the encryption that happened client side. We never store or ever see your private key, we have zero web tracking (the exception your IP only used for tracking auth tokens so you as a user can revoke them)

4: We also allow you to save meta data about the site such as their preview image, tags and notes, this makes reviewing your bookmarks a much more enjoyable experience vs just looking at the title.

5: We are just simply bookmarks, by keeping the ui simple and distraction free don't overwhelm you when you just need to navigate to your bookmarks.

6: Our plugin focuses on fast and simple, one click add bookmark operations.

7: We don't data mine you, the only thing we know about you is your email used to register and the total number of bookmarks you have, that's it. We will never sell or share anything about you with anyone ever.