The Advanced of Fuzzy Vault Using Password - Advances in Computational Science and Engineering - page 35

To make secret S secure, secret S is encoded by the coefficients of a polynomial F,
and secret S is locked using a random set of elements A. F(aS) is constructed from A
and F(a) that 'a' is an element of set A. We generate randomly chaff points. Then, we
generate vault V that chaff point are added to F(aS).
Fig. 3. Decryption of fuzzy vault scheme
We consider that want to decrypt secret S. We generate set A randomly as above.
Overlapping both vault V and set A, we can obtain many points that lie on F. Using
error correcting code, we can reconstruct F and obtain secret S. We describe biometric
fuzzy vault next section in the concrete.
2.3 Fingerprint
Fingerprint is the process of comparing questioned and known friction skin ridge
impressions(Minutiae) from fingers or palms or toes to determine if the impressions
are from the same finger or palm. The flexibility of friction ridge skin means that no
two finger or palm prints are ever exactly alike, even two impressions recorded im-
mediately after each other. A known print is the intentional recording of the ridges
with black printers ink rolled across a contrasting white background, typically a white
card. Friction ridges can also be recorded digitally using a technique called Live-
Scan. Figure 4 represents logic system.
Fig. 4. Fingerprint construction
2.4 Fuzzy Vault Scheme for Fingerprint
Umut Uludag proposed the new scheme[3]. This scheme describes authentication
mechanism using biometric information which has several advantages over password-
based systems. But this scheme must compute n+1 combination to make n-th degree
polynomial to decrypt and so execution time of decryption process is too long.