Cryptographic Key Length Recommendation
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In most cryptographic functions, the key length is an important security parameter. Both academic and private organizations provide recommendations and mathematical formulas to approximate the minimum key size requirement for security. Despite the availability of these publications, choosing an appropriate key size to protect your system from attacks remains a headache as you need to read and understand all these papers.

This web site implements mathematical formulas and summarizes reports from well-known organizations allowing you to quickly evaluate the minimum security requirements for your system. You can also easily compare all these techniques and find the appropriate key length for your desired level of protection. The lengths provided here are designed to resist mathematic attacks; they do not take algorithmic attacks, hardware flaws, etc. into account.

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© 2026 BlueKrypt - v 32.3 - May 24, 2020
Author: Damien Giry
Approved by Prof. Jean-Jacques Quisquater
Contact:
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I would like to thank Prof. Arjen K. Lenstra for his kind authorization and comments.
Surveys of laws and regulations on cryptology: Crypto Law Survey / Digital Signature Law Survey.
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