US Patent 11212090 Derived unique random key per transaction

In one arrangement, a method for using symmetric keys between two entities comprising a device and a host include initiating, by the device, a transaction involving original data, wherein the original data needs to be verified by the host. The method further includes deriving, by the device, a first key based on a previously generated key and a first number, wherein the first key is unique to the transaction, and the first number is randomly generated. The method further includes sending, by the device, the first key to the host for verification.