User authentication is a method for authenticating a user. It is conducted by another
party that communicate with the user. Usually, the authentication is done using veri -
cation of username, password, and biometric. There was a method proposed by Seung
.et.al where the user authentication process was done using biometric ( ngerprint) and
password. However, the authentication can be succeeded by authenticating the user based
on the password or the ngerprint. Thus, a fake user who knows the password of the
legitimate user may be authenticate as the legitimate user without examining the nger-
print. Besides, the time complexity of the previous method for authentication process is
high. Furthermore, there is opportunity of fake authenticator device for obtaining the
ngerprint and password of the legitimate user because there is no authentication process
for examining whether the device is the legitimate one. This problem can be solved using
Elliptic Curve and Keccak Hash Function. The Elliptic Curve is used for conducting device
authentication for examining whether the device is a legitimate one, while Keccak Hash
Function is used for improving the user authentication process, such that the authentica-
tion process can be succeeded only if both password and ngerprint is authenticated. The
result of experiment shows that the user authentication processing time decreased 35.06
ms - 41.6 ms compared with the method proposed by Seung .et.al, while the probability of
obtaining the ngerprint and password using the proposed method is less than the previous
method of 2????^-57. It is proven that the proposed method is strong against fake device attack
for stealing the biometric information and password.
Keywords: Authentication, Elliptic Curve, Keccak Hash Function.