Updating biometric template protection keys

Methods and devices for updating biometric template protection keys can include updating at least one stored feature transformation key with which a set of biometric data of a user initially has been transformed at a first client device at which the biometric data of the user was captured and enrolled with a network node, which set of transformed biometric data of the user is stored at a biometric data verification node that does not have access to the feature transformation key. The method comprises generating random data, computing at least one new feature transformation key based on said random data, replacing the at least one stored feature transformation key with the computed at least one new feature transformation key, and transmitting the generated random data to the biometric data verification node, which uses the generated random data to update the at least one set of transformed biometric data.