FIDO2
Fast Identity Online 2
An authentication standard enabling passwordless login through hardware security keys or biometrics using public key cryptography.
技術的詳細
FIDO2's security rests on the computational difficulty of factoring large semiprimes. Key sizes: 2048-bit is the current minimum, 4096-bit is recommended for long-term security. RSA is ~1000x slower than AES, so it's typically used to encrypt a symmetric session key (hybrid encryption). RSA signing uses the private key; verification uses the public key — the reverse of encryption. OAEP padding (PKCS#1 v2) is required; the older PKCS#1 v1.5 padding has known vulnerabilities (Bleichenbacher's attack).
例
```javascript
// FIDO2 — Web Crypto API example
const data = new TextEncoder().encode('sensitive data');
const hash = await crypto.subtle.digest('SHA-256', data);
const hex = Array.from(new Uint8Array(hash))
.map(b => b.toString(16).padStart(2, '0')).join('');
```
関連ツール
P
Password Generator
P
Password Strength Checker
H
Hash Generator
H
HMAC Generator
A
AES Encrypt / Decrypt
R
Random String Generator
C
CSP Header Generator
T
Text Redactor
C
CORS Header Generator
S
SRI Hash Generator
B
Base64 Encoder / Decoder
J
JWT Decoder
U
UUID Generator
T
TOTP Configurator
S
SSL Certificate Decoder