A novel key retrieval algorithm for phase-coding based on double-key segmented composite filtering(SCF) is proposed.During the recovering,at first the segmented phase mask(SPM) of SCF coding system was obtained by the known-plaintext attack.Then,according to the content of the mask,the affiliations of the phase mask were analyzed by Monte Carlo method.On that basis,the intensity distribution of the key,which needs to be retrieved,could be confirmed depending on the regulation of SPM generation.D...