Comparison of Time and Money Needed to Break Different Length Keys
Length of Crytographic Key
| Cost | 40-bit | 56-bit | 64-bit | 80-bit | 128-bit |
|---|---|---|---|---|---|
| $0.1 M | 2 sec. | 35 hrs. | 1 yr. | 70000 yrs. | 10E19 yrs. |
| $1.0 M | .2 sec. | 3.5 hrs. | 37 days | 7000 yrs. | 10E18 yrs. |
| $100 M | 2 millisec. | 2 min. | 9 hrs. | 70 yrs. | 10E16 yrs. |
| $1.0 B | .2 millisec. | 13 sec. | 1 hr. | 7 yrs. | 10E15 yrs. |
| $100 B | 2 microsec. | 1 sec. | 32 sec. | 24 days | 10E13 yrs. |
Secret-Key and Public-Key Lengths for Equivalent Levels of Security
| Secret-Key Length | Public-Key Length |
|---|---|
| 56 bits | 384 bits |
| 64 bits | 512 bits |
| 80 bits | 768 bits |
| 112 bits | 1792 bits |
| 128 bits | 2304 bits |