Memory control circuitry controls access to data stored in memory, and memory security circuitry generates encrypted data to be stored in the memory. The encrypted data is based on target data and a first one-time-pad (OTP). In response to an OTP update event indicating that the first OTP is to be updated to a second OTP different from the first OTP, the memory security circuitry generates a re-encryption value based on the first OTP and the second OTP, and the memory security circuitry to issues a re-encryption request to cause updated encrypted data to be generated in a downstream component based on the encrypted data and the re-encryption value and to cause the encrypted data to be replaced in the memory by the updated encrypted data.