A method for performing binary searches related to biometric information, for finding a matching biometric identifier, such as a fingerprint, palm print, face recognition, DNA or voice sample, in a biometric database, wherein a first index table related to the biometric database comprises a number of first key values, each first key value being associated with a first index value, the first index values pointing to information comprised within the biometric database; characterised by comprising: generating a binary search key representing one or more biometric features belonging to the biometric identifier of an individual to be searched; partitioning the binary search key into at least two sub-keys, each sub-key comprising a predetermined number of bits; obtaining a set of second index tables (Table1-Table4) each comprising a plurality of second key values, each second key value being associated with a corresponding second index value, wherein the number of second index tables in the set is equal to the number of sub-keys within the binary search key; identifying, in a first one (Table1) of said set of second index tables (Table1-Table4), at least one second key value matching a first sub-key of the binary search key; obtaining, for each identified second key value, a corresponding second index value pointing to a limited portion of second key values in a next second index table; identifying, in said limited portion of said next second index table, at least one second key value matching a next sub-key of the binary search key; repeating the steps of obtaining second index values and searching a limited portion of a next second index table until all sub-keys of the binary search key have been searched; wherein the second index value corresponding to a match to a last second key within a last second index table points to one or more records comprised in the biometric database, wherein one or more matching results regarding biometric information corresponding to the binary search key are obtained, the records relate to a biometric identifier belonging to an individual; and returning a result when the last sub-key of the binary search key has been searched; repeating the above steps 1-8 for a plurality of binary search keys together representing the biometric identifier; obtaining a matching biometric identifier having a largest number of record hits after searching the plurality of binary search keys; wherein the first key values are not unique, such that several records within the biometric database result from a single search for the binary search key; wherein the predetermined number of bits of the first sub-key is 16, and the first index table (Table1) comprises 256*256 values, or wherein the predetermined number of bits of the first sub-key is 8, and the first index table (Table1) comprises 256 values, and wherein the predetermined number of bits of the next sub-key is 8, and the limited portion of the next index table comprises at most 256 values. generating a binary search key representing one or more biometric features belonging to the biometric identifier of an individual to be searched; partitioning the binary search key into at least two sub-keys, each sub-key comprising a predetermined number of bits; obtaining a set of second index tables (Table1-Table4) each comprising a plurality of second key values, each second key value being associated with a corresponding second index value, wherein the number of second index tables in the set is equal to the number of sub-keys within the binary search key; identifying, in a first one (Table1) of said set of second index tables (Table1-Table4), at least one second key value matching a first sub-key of the binary search key; obtaining, for each identified second key value, a corresponding second index value pointing to a limited portion of second key values in a next second index table; identifying, in said limited portion of said next second index table, at least one second key value matching a next sub-key of the binary search key; repeating the steps of obtaining second index values and searching a limited portion of a next second index table until all sub-keys of the binary search key have been searched; wherein the second index value corresponding to a match to a last second key within a last second index table points to one or more records comprised in the biometric database, wherein one or more matching results regarding biometric information corresponding to the binary search key are obtained, the records relate to a biometric identifier belonging to an individual; and returning a result when the last sub-key of the binary search key has been searched;