A method herein is for encryption key update in a station. In the method, a first data block is encrypted using a first plurality of round keys over a first plurality of rounds to generate a first encrypted data block, wherein the first plurality of round keys are generated based on an initial block key. A round key of the first plurality of round keys is retained for use as a basis for a first derived block key. A second data block is encrypted using a second plurality of round keys over a second plurality of rounds to generate a second encrypted data block, wherein the second plurality of round keys are generated based on the first derived block key. A round key of the second plurality of round keys may be retained for use as a basis for a second derived block key.