Encryption key strengths
Encryption systems are often grouped into families of symmetric (single key) and asymmetric systems (a key to encrypt and another to decrypt). They also can be grouped according to the central algorithm used, such as elliptic curve cryptography. Here are some standard key sizes and the level of protection they provide.
|
Symmetric |
Asymmetric |
Elliptic Curve |
Applications |
|
80-bit* |
1,024-bit RSA |
160-bit |
Ephemeral data, i.e. stock trades |
|
112-bit |
2,048-bit RSA* |
224-bit |
E-commerce, Internet banking |
|
128-bit |
3,072-bit RSA* |
256-bit |
Classified to secret level |
|
192, 256-bit |
15,360-bit RSA |
512-bit |
Highly sensitive, top secret |
*80-bit keys are valid until 2010, according to the National Institute of Standards and Technology
*2,048-bit sufficient until 2030, according to RSA
*3,072-bit sufficient beyond 2030, according to RSA
Source: National Institute of Standards and Technology, RSA