scan and used for encryption of the private key the article by john daugman entitled u201c how iris recognition works u201d referred to above suggests that several such as about 10 offsets of the obtained sequence may be tried before correct alignment is achieved in the present application the same sequence is used for encryption of a private key and therefore it is not known whether the correct alignment has been achieved or not a possible solution comprises incorporation of an extra field of 20 bits into the encrypted private key once the private key has been restored the content of this field may be compared with the first 20 output bits of a hash e g sha 1 of the private key if these bits do not agree a different offset of the 2000 computed iris bits may be tried this offset sequence may be used for decryption of the private key this process may be continued until agreement is reached at which point the correct value for the private key may be set the above process is typically characterized in that iris fuzzy information is used not for creation of the private public key pair but for encryption and decryption of the private key therefore using fuzzy information and error correcting codes the same private key may be obtained repeatedly alternatively a content key may be generated as shown in fig3 a suitable eye measurement or concatenation of eye measurements from eye recognition unit 70 forms a value having say 2000 bits it being appreciated that numerical values stipulated.