from Hacker News

I find myself wanting to quickly parse/decode/unescape sensitive data via randomly found sites but cannot. I wonder if there is an existing solution to making sure a random base64 encoder site will not phone home with my data.

Specific use cases:

- Parse a JWT using jwt.io

- Encode/unescape/parse data from a specific format (base64, protobuf, ...)

- Hashing a password

- Generating Bitcoin wallet using bitaddress.org

The solutions I end up doing:

- Finding a way to do it offline (in a terminal) or using/writing a script I can safely audit.

- Load up a VM, load the site, cut it from network, make use of the site and throw away the VM.

I am debating on creating a Browser extension to solve this problem, but wanted to get ideas from you to see if I am missing something that already exists.

The extension would have an isolate functionality that would:

- Cut off network access for a tab

- Cut off access to other tabs (Not sure how to do this, temporary containers in Firefox?)

- Listen for tab close event and clear all browser data for that site (cookies, storage, workers, history etc...)

What do you think?