In an example, a computing device is described. The computing device comprises a processor. The processor is to generate a key using a value as an input to generate the key. The processor is further to, in response to generating the key, exclude the value from future use as the input. The processor is further to store an indication of a subsequent value to use as the input to generate a subsequent key. The indication is cryptographically associated with an entity to control third-party access to the indication.