What it is
Secure client-side cryptography without a backend.
CryptoManager is a fully client-side key management tool. Keys are generated with the browser’s Web Crypto API, stored in localStorage, and never sent to a server. Use it to experiment with modern algorithms, protect notes or files locally, and keep related keys grouped into collections.
The live app runs at cryptomanager.joshigiri.sh. This page is the project overview; the subdomain is the tool itself.
Features
Key generation
Create AES-GCM, AES-CBC, RSA-OAEP, ECDH, ECDSA, and Ed25519 keys with cryptographically secure randomness.
Collections
Organize keys by project or purpose. Search, edit, export, and import collections as JSON backups.
Encrypt & decrypt
Encrypt text or files. AES-GCM supports Additional Authenticated Data (AAD) when you need it.
Sign & verify
Produce and check digital signatures with ECDSA (P-256) or Ed25519 for message authenticity.
Export formats
Export keys as JWK (native) or simplified PEM for use with other tools and workflows.
Local only
No accounts, no cloud sync. Everything stays in your browser until you export a collection yourself.
Supported algorithms
| Category | Algorithms |
|---|---|
| Encryption | AES-GCM, AES-CBC, RSA-OAEP (2048 / SHA-256), ECDH (P-256 → AES-GCM) |
| Signing | ECDSA (P-256 / SHA-256), Ed25519 |
Privacy & limits
Useful for local work and learning — not a production KMS.
- Keys live in browser localStorage unencrypted. Anyone with access to the profile can read them.
- Clearing site data, another browser, or a different device will not see your vault unless you import a backup.
- Prefer dedicated key management (HSM / cloud KMS) for production secrets and long-term private keys.