ProtectedShare vs PrivateBin

PrivateBin is a pastebin. With the default settings a paste can stay up for a year or never expire, carry a discussion thread, and be shown as Markdown or highlighted source code. That suits code snippets and logs you want to keep around and link to.

ProtectedShare is built for the opposite: getting a secret to one person, then deleting it. Every share expires within 30 days. Notes can burn after the first read, EnvShare secrets allow 1 to 100 reads, and a job removes expired rows every 30 minutes.

PrivateBin is software that anyone can run. Its website has a “Try it out” link and keeps a directory of public instances, with checks such as HTTPS and an Observatory rating. Each operator picks the settings: file uploads are off by default, the default size limit is 10 MB, and the expiry options can change.

Its README is candid that you have to trust the server administrator not to inject malicious code. That holds for every tool that encrypts in the browser, ProtectedShare included, because the server delivers the code. The mitigations are the same as well: source code you can read, and running your own copy. The self-host guide shows how.

Both encrypt with AES-256-GCM in the browser and keep the key in the URL fragment, so the server stores only ciphertext. As PrivateBin's README points out, anyone holding a full link to a paste without a password can read it. The same goes for a ProtectedShare link that carries its key.

ProtectedShare also puts a gate in front of the ciphertext. HKDF derives an auth token from your key or password, the server stores only its hash, and it hands over the ciphertext only to a browser that presents the token. Link previews in chat apps fetch without the fragment, so they can't open, or burn, a note. The security page has the details.