The present invention relates to a method to manage a One Time Password key, referenced OTP key, used in an OTP algorithm in a user device having access to an unsafe storage including the steps of retrieving a Personal Identification Number, named PIN, of a user of the user device, deriving a symmetric key from the PIN, encrypting the OTP key using the derived symmetric key, storing the encrypted OTP key in the unsafe storage, decrypting the OTP key using the derived symmetric key, and generating a next OTP key using an incremental parameter, wherein the start value of the incremental parameter of the OTP key generation is random.