Generate 2048-bit RSA Key Pair
Generate a 2048-bit RSA key pair online. Learn why 2048-bit is the current standard minimum key size and when it is appropriate for your security requirements.
Detailed Explanation
Generating a 2048-bit RSA Key Pair
A 2048-bit RSA key is currently the minimum recommended key size for production use. The "2048-bit" refers to the length of the modulus n in the RSA key pair, which directly determines the cryptographic strength.
Why 2048-bit?
The security of RSA keys is measured in terms of equivalent symmetric key strength:
| RSA Key Size | Symmetric Equivalent | Status |
|---|---|---|
| 1024-bit | ~80-bit | Deprecated — factorable with modern resources |
| 2048-bit | ~112-bit | Acceptable — standard minimum through ~2030 |
| 3072-bit | ~128-bit | Recommended — NIST guidance for longer term |
| 4096-bit | ~140-bit | Strong — for high-security applications |
Generating with Web Crypto API
const keyPair = await crypto.subtle.generateKey(
{
name: "RSA-OAEP",
modulusLength: 2048,
publicExponent: new Uint8Array([1, 0, 1]), // 65537
hash: "SHA-256",
},
true, // extractable
["encrypt", "decrypt"]
);
Performance Characteristics
2048-bit keys offer a good balance between security and performance:
- Key generation: ~100-500ms on modern hardware
- Encryption: ~1ms for small payloads
- Decryption: ~10-50ms
- Signature creation: ~10-50ms
- Signature verification: ~1ms
When to Use 2048-bit
- Standard web server TLS/SSL certificates
- SSH authentication for typical workloads
- API authentication tokens with regular rotation (< 2 years)
- Development and testing environments
When to Choose Larger Keys
If your data needs to remain secure beyond 2030 or you operate in a regulated industry (finance, government, healthcare), consider 3072-bit or 4096-bit keys instead.
Use Case
2048-bit RSA keys are suitable for most everyday security needs including SSH access, TLS certificates with standard validity periods, and JWT signing tokens that are rotated regularly. They provide a practical balance of security and computational efficiency for web applications and services.