US Patent 9300464 Probabilistic key rotation

Information, such as a cryptographic key, is used repeatedly in the performance of operations, such as certain cryptographic operations. To prevent repeated use of the information from enabling security breaches, the information is rotated (replaced with other information). To avoid the resource costs of maintaining a counter on the number of operations performed, decisions of when to rotate the information are performed based at least in part on the output of stochastic processes.