**5. Conclusion**

In a holistic survey on soft biometrics for user identification, we have seen that there is no one best biometric technology since it depends on the application requirement. A zero false acceptance rate is needed, for example, in security, and the false rejection rate needs to decrease, but in the civilian application, we need the opposite, so for any biometric system, we need to find a good balance between authentication reliability and complexity. As a result, traditional biometrics suffer from low recognition rate because they need cooperation with the user, operate in the controlled environment, and introduce privacy concern. So using multi-biometrics is the solution, but still, the system suffers from computation cost and long processing steps. However, another possible solution is to use soft biometrics to increase the population coverage and decrease the system cost and complexity.
