For creating multi-biometric cryptosystem, multiple theories proposed by different authors in their papers published must be referred. Multi-biometric systems accumulate evidence from more than one biometric trait (e.g., face, fingerprint and iris) in order to recognize a person. They provide higher recognition accuracy and larger population coverage. Multi-biometric systems could be implemented using fuzzy vault as well as fuzzy commitment. The feature level fusion could be implemented using different embedding algorithms. The online authentication is implemented using the unibiometric fingerprint authentication system.