In many applications, cryptography happens behind the scenes in a server-side 'black box.' When building the RSA Message Encryption Demo, I wanted to bring that logic directly into the browser, using Web Cryptography API to make the process transparent and interactive.
When I set out to build the RSA Message Encryption Demo for OnlineToolsX, I wanted to pull back the curtain while maintaining a strict "privacy-first" philosophy.
Privacy by Default: The Power of Client-Side Processing
The biggest flaw in many online utility tools is that they require you to send sensitive data to a server. When dealing with RSA keys, that’s a non-starter.
By architectural choice, this tool performs 100% of the processing in your browser.
- Zero Server Footprint: Your private keys and plain-text messages never touch a database or a backend log.
- Instant Execution: By using Web Cryptography API, the encryption happens locally, providing immediate feedback without network latency.
A Living Laboratory for RSA
I designed this demo to be more than just a utility; it’s a learning sandbox. Instead of just reading about asymmetric encryption, you can practically see how the two keys interact. You can input a message, encrypt it with a public key, and then use the private key to bring it back to life—all in one clear, visual flow.
Top comments (2)
This is a solid foundation, especially the client-side, no-server approach. Once you’re comfortable with this pattern, a cool next step could be experimenting with verifiable execution instead of just local execution.
For example, running sensitive crypto logic inside TEEs and exposing proofs of correct execution, something blockchains like Oasis focus on, opens up use cases like shared encryption workflows, policy-based signing, or collaborative tools where multiple parties need guarantees without trusting a backend.
Feels like this demo could evolve into a broader “privacy-first crypto playground” if you ever want to explore that direction.
Nice demo!! Client-side crypto is the right call here, no server trust, no key exposure, and it makes the learning experience much clearer than a black-box API.
This kind of pattern also maps well to where privacy infra like Oasis is heading: keep sensitive logic and data local or confidential, while still integrating with verifiable systems when needed. Solid example of privacy by architecture, not policy.