Nonce Reuse
Definition
Nonce reuse uses a security value intended to be unique more than once.
The repeated use of a value intended to be unique within the same cryptographic key context.
Simply explained
A number that should occur only once under the same key is accidentally used again.
Why it matters in practice
Helps develop and operate digital systems robustly, securely, and maintainably.
Example from business
A service generates the same nonce sequence after restart under an unchanged key.
Limits and pitfalls
- Generate nonce only randomly and without collision strategy or do not persist counter states.
Origin & history
Many stream ciphers and AEAD schemes require unique nonces; reuse can break confidentiality and authenticity.
Use in mid-sized companies
- Possible application: A service generates the same nonce sequence after restart under an unchanged key.
Frequently asked questions
What does nonce reuse mean?
The repeated use of a value intended to be unique within the same cryptographic key context.
Which mistakes should be avoided?
Generate nonce only randomly and without collision strategy or do not persist counter states.
Sources
Source checked on 10.10.2026. Editorial application examples are hypothetical; no evidence of real customer results.
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