AES ALGORITHM FOR ATM BANKING SYSTEMS

By,Prasanna Prashant Under the guidance of , Prof.S.G.Kulkarni

AES ALGORITHM FOR ATM BANKING SYSTEMS

By,Prasanna Prashant Under the guidance of , Prof.S.G.Kulkarni

Contents:Introduction Existing Banking ATM System Background Of Advanced Encryption Standard(AES) Embedded Crypto-Biometric Authentication Protocol Encryption and Decryption Algorithms Applications and Limitations Conclusion References

EXISTING BANKING ATM SYSTEM:

Limitations of Existing ATM System: The most recent cases show that the thefts have used sophisticated cracking programs to steal ATM holders. It is required to remember PIN number for the ATM card holders. Sometimes they are confusing, difficult to be recalled immediately which of course can lead to a serious problem. The strength of PIN as a security system is weakened since the likelihood of the code leaking to other people has increased.

Most commonly PINs are 4-digit numbers in the range 0000-9999 resulting in 10,000 possible numbers, so that an attacker would need to guess an average of 5000 times to get the correct PIN. ATMs present to people with a variety of disabilities, particularly examining the access barriers experienced by the people who are blind, vision impaired or who have reading, learning or intellectual disabilities.

BACKGROUND OF ADVANCED ENCRYPTION STANDARD (AES) Advanced Encryption Standard (AES) is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data. Originally called Rijndael, the cipher was developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, and submitted by them to the AES selection process. The name Rijndael is a play on the names of the two inventors. AES is the name of the standard, and the algorithm described is a (restricted) variant of Rijndael. However, in practice the algorithm is also referred to as "AES"

EMBEDDED CRYPTO-BIOMETRIC AUTHENTICATION PROTCOL Generally, there are two basic fingerprint authentication schemes, namely the local and the centralized matching. In the central matching scheme, fingerprint image captured at the terminal is sent to the central server via the network and then it is matched against the minutiae template stored in the central server

There are three stages in the protocol namely registration, login and authentication. In the registration phase, the fingerprints of ATM users are enrolled and the derived fingerprint templates are stored in the central server. The login phase is performed at an ATM terminal equipped with a fingerprint sensor. The proposed block schematic of embedded crypto biometric authentication system is shown in Fig

In the authentication phase, the fingerprint image is then encrypted and transmitted to central server via secured channel. At the banking terminal the image is decrypted using 128 bit private key algorithm. The encrypted image is transmitted to the central server via secured channel. At the banking terminal the image is decrypted using the same key. Based on the decrypted image, minutiae extraction and matching are conducted to verify the presented fingerprint image belongs to the claimed user. The authentication is signed if the minutiae matching are successful.

ENCRYPTION KEY

IMAGE PREPROCESSING

IMAGE ENCRYPTION

CENTRAL SERVER

ACCESS GRANTEDMATCHING

FINGERPRINT TEMPLATESSingularity Frequency Minutiae

YES

IMAGE DECRYPTION DECRYPTION KEY

MINUTIAE EXTRACTION

NO

ACCESS DENIED

ENCRYPTION AND DECRYPTION ALGORITHMS Encryption is the process of converting plain image into cipher image. Plain image in our paper is the unsecured form of fingerprint image. By using the appropriate keys, plain image is encrypted into cipher image before transmitting through the secured channel. Decryption is the reverse process of encryption. Fingerprint image is recovered (plain image) by using the same key. DES, Triple DES and AES algorithms are the commonly used symmetric key algorithms. Shared key, less time consumption, easy operation and secret key are the merits of symmetric key algorithms.

AES has a fixed block size of 128 bits and a key size of 128, 192, or 256 bits, whereas Rijndael can be specified with block and key sizes in any multiple of 32 bits, with a minimum of 128 bits. The block size has a maximum of 256 bits, but the key size has no theoretical maximum. AES consists of following steps: 1)Key Generation. 2)Initial Round. 3)Rounds.

High-level description of the algorithm1. Key Expansion: Round keys are derived from the cipher key using Rijndael's key schedule. 2.Initial Round (i) AddRoundKey: Each byte of the state is combined with the round key using bitwise xor.

3.Rounds (i)SubBytes: A non-linear substitution step where each byte is replaced with another according to a lookup table.

(ii) ShiftRows: A transposition step where each row of the state is shifted cyclically a certain number of steps.

(iii) MixColumns: A mixing operation

which operates on the columns of the state, combining the four bytes in each column

(iv) AddRoundKey: Each byte of the state is combined with the round key; each round key is derived from the cipher key using a key schedule

4. Final Round (no MixColumns) : a.SubBytes. b.ShiftRows. c.AddRoundKey.

(a)

(b)

(c)

(d)

Fingerprint and the encrypted image. (a) Original image; (b) One round of iteration; (c) Two rounds of iterations; (d)Three rounds of iterations.

Use case diagram for our system design

Sequence diagram for Use case model

APPLICATIONS OF AES: Electronic commerce transactions. ATM machines. Wireless communications, such as wireless keyboards. Virtual Private Networks (VPN). Point-of-sale terminals. Surveillance applications.

CONCLUSION:An embedded Crypto-Biometric authentication scheme for ATM banking systems has been proposed. The claimed users fingerprint is required during a transaction. The fingerprint image is encrypted and then transmitted to the central server using symmetric key algorithm. The encryption keys are extracted from the random pixel distribution in a raw image of fingerprint, some stable global features of fingerprint and/or from pseudo random number generator. Different rounds of iterations use different keys.At the banking terminal the image is decrypted using the same key. Based on the decrypted image, minutiae extraction and matching are performed to verify the presented fingerprint image belongs to the claimed user.

References: F.Han, J.Hu, X.Yu, Feng, Zhou: A New Way of Generating Grid-Scroll Chaos and its Application to Biometric Authentication, IEEE, (2005) 61-66 U.Uludag, S.Pankanti, S.Prabhakar andA. K.Jain,Biometric cryptosystems: Issue and challenges, Proceedings of the IEEE, vol.92, no.6, 2004, pp.948-960

Jain, A.K., Prabhakar, S., Hong, L., Pankanti, S.:Filterbank-based fingerprint matching, IEEE Trans. on Image Processing, 9 (2000) 846-859 A Method to Improve the Security Level of ATM Banking Systems Using AES Algorithm, N.Selvaraju & G.Sekar, International Journal of Computer Applications (0975 8887) Volume 3 No.6, June 2010 Diniz, E. (1998) Web Banking in USA. Journal of Internet Banking and Commerce Singh, B. and Malhotra, P. (2004) Adoption of Internet banking: An empirical investigation of Indian banking Sector. Journal of Internet Banking and Commerce