๐ Cryptographic Key Strength Reference
Symmetric (AES, etc.)128-bit
RSA/DH key length3,072-bit
ECC key length256-bit
Reference table
| Symmetric (AES, etc.) | RSA/DH key length | ECC key length |
|---|---|---|
| 80 | 1,024 | 160 |
| 112 | 2,048 | 224 |
| 128 | 3,072 | 256 |
| 192 | 7,680 | 384 |
| 256 | 15,360 | 521 |
Compare symmetric key sizes (like AES) against the RSA/DH key length and ECC (elliptic curve) key length needed for equivalent security strength. Based on the widely cited approximate equivalences from NIST SP 800-57.
How to use
- Select the symmetric key size you want to check.
- The equivalent RSA/DH and ECC key lengths are shown automatically.
- See the full reference table below for all sizes.
FAQ
Why do different key types need such different bit sizes?
Factorization- and discrete-log-based algorithms like RSA and DH need much larger key sizes than symmetric ciphers (AES) or elliptic curve cryptography (ECC) to reach the same security level.
How secure is 128-bit AES?
128-bit AES is considered roughly equivalent in strength to a 3072-bit RSA/DH key or a 256-bit ECC key.
Are these numbers absolute?
No, these are general guidelines from NIST SP 800-57. Actual security also depends on implementation quality and advances in attack techniques.