Techniques for automatically generating test data solve various problems in test data generation. A technique of automatically generating test data includes receiving a signature to be embedded in at least one character string to be generated and determining a total sum of attribute values intrinsic to characters in the character string. The sum is associated with each element of the signature. At least one of the characters in the character string may be selected from a character table describing characters prepared to create the test data so as to achieve the determined total sum for each element of the signature. The generated test data contains the character string including the selected character.