RSA / ECDSA キーペアジェネレーター

よくある質問

Quick answers.

›Is it safe to generate private keys in a browser?

Yes, provided the tool uses the standard Web Crypto API and does not transmit data. This tool runs entirely client-side, meaning your private key is never sent to a server or stored in a database.

›What is the difference between RSA and ECDSA?

RSA is the traditional standard based on large prime numbers, widely compatible but requiring larger key sizes for security. ECDSA uses elliptic curve cryptography to provide equivalent security with much smaller keys, resulting in faster computations and less storage.

›Which curve should I choose for ECDSA?

P-256 (prime256v1) is the most common choice for general web applications and is widely supported by cloud providers. P-384 and P-521 offer higher security margins if required by specific compliance standards.

›What format should I download?

Use PEM or PKCS#8 for server-side environments like Node.js, Python, or OpenSSL. Choose JWK (JSON Web Key) if you are building browser-based applications that need to import keys directly back into the Web Crypto API.