A Bio-Hashing Technique for Authentication

• Biometric Image

• Hashing Function

Step 1Bio-Hashing

• Password Encryption

• Image Encryption

Step 2Encryption

• Confirmation of Identity

Step 3Authenticati

on

Mentor:Dr.Debasis Giri,Professor, Dept. of CSE,Haldia Institute of Technology

By:Ankit Agarwal (12/CS/061)Tuhin Kundu (12/CS/165)Bachu Paul (12/CS/072)Anish Kumar (12/CS/060)

Introduction Types Of Cryptography Major Encryption Image Encryption Methods Cellular Automata Langton’s Ant Cellular Automata Gray Code based Image encryption BlowFish Algorithm Limitations and vulnerabilities Next stage of planning Conclusion Bibliography

Outline

Biometrics:It is the science of establishing the identity of an individual based on the physical, chemical or behavioral attributes of the person. Ex.-Fingerprint

Encryption is the most effective way to achieve data security. Hera many types of image encryption algorithms are used for encrypting the biometric image.Image encryption techniques try to convert original image to another image that is hard to understand; to keep the image confidential between users, in other word, it is essential that nobody could get to know the content without a key for decryption.

Authenticated Encryption (AE) is a block cipher mode of operation which simultaneously provides confidentiality, integrity, and authenticity assurances on the data; decryption is combined in single step with integrity verification

Hash function means a function that compresses, meaning the output is shorter than the input. Often, such a function takes an input of arbitrary or almost arbitrary length to one whose length is a fixed number, like 160 bits, considered practically impossible to invert.

Introduction

TYPES OF CRYPTOGRAPHYo Symmetric Key:- It uses only one key to encrypt and

decrypt data. Ex:- DES, 3- DES, RC5, AES, BA

o Asymmetric Key:- Public Key are used for encryption process while private key are used for decryption.

Ex:-RSA, Digital Signatureo Secret Key plays an important role in symmetric block

cipher where the algorithm’s strength depends on the key size.

Traditional Algorithms like Triple- DES, IDEA, AES are developed for textual information have been found not suitable for image encryption due to intrinsic features of image such as:

1) Large data size2) Existence of bulk data capacity3) Strong correlation between adjacent pixels4) High redundancy

Major Encryption Apart from conventional encryption schemes there exist some selective techniques like Edge maps, Region of interest and Entropy based techniques. One such method is in which the whole image is divided into :

1) The region of interest ( ROI ) which contains the significant information.2) The region of background ( ROB ) which contains the insignificant information.An algorithm to select the ROI

Read the input image into an M X N matrix J of 24- bit integers (8 bits for each RGB band).The parameters T and S represent the statistical threshold and the block size, Partition J into P = MN/S2 blocks B1, B2, ……..Bp of size S X S.For k from 1 to p:

Let Cij denote the ( i,j )- entry of Bk and let C’ be the mean of the entries of Bk

Let e = ∑i=1s ∑j=1

s | Cij – C’|If e > T

Flag Bk as part of ROIElse

Flag Bk as part of ROBEnd

End

Image Encryption MethodsChaos System

It studies the behavior of dynamical systems that are highly sensitive to initial conditions.

Many fundamental properties of chaos system are analogous to ideal cryptographic properties for image encryption.1. Ergodicity2. Sensitivity to initial conditions3. Random like behavior4. Mixing effect

Most of the chaotic based architecture contains two main stages:5. Confusion 6. Diffusion

The Confusion and Diffusion properties are implemented by applying substitution and permutation boxes.

Cellular Automata

Is a Discrete Dynamical System Comprised of grids Each grids change its state according to

the states of peripheral cells Proposed for public key cryptography One way function is the evaluation of

Finite Cellular Automata Ex.- Langton’s Ant Cellular Automata

Langton’s Ant Cellular Automata

An example of Cellular Automata Main Principle :

There are Cells,either black or whiteAn Ant crawls on it by the following rule :

a) If the Ant is in Black Grid,it turns right & in White Grid it turns left by 90°

b) Next it will move forward & change the Black grid to white and white to Black

Used in Encryption to scrample the image

Study of an algorithm on Image Encrytion

It uses Cellular Automata and Intertwining Logistic Map & PWLCM Map

Imagine Image as a chessboard & apply the Langton’s Ant Cellular Automata and Intertwining Logistic Map to scramble the image

Now Apply PWLCM map to diffuse the image To increase randomness this algorithm

changed the Cellular Automata using Chaos Maps

Security Analysis Key Space Analysis:

Key space should be large enough Make Brute Force attack infeasible

Statistical Analysis: Algorithm needs to have good randomness Cipher image should be confusing enough that attacker don’t

get any statistical information Sensitivity Analysis:

Make sure that algorithm is very sensitive to initial values Co-relation Analysis:

Co-relation between adjacent pixels in encrypted image should be low

Gray Code based Image encryption

Two functions :1. ( n,k,d )- Gray-Code: G = A XOR ( A>>( d + 1) )2. Gray- decimal ( x,k,d ): x1 = Gray- decimal( x,k,d1 ) XOR of1 and x2 = Gray-

decimal( x,k,d2 ) XOR

of2Steps involved:3. Use BGCBPA4. Transport the resultant image5. Then again use BGCBPA

BlowFish Algorithm

For i= 1 to nL(i) = R(i-1)R(i) = L(i-1) XOR F(R(i-1),k)

Limitations and vulnerabilities1.Recent cryptanalytical works have demonstrated that some chaos- based image Cryptosystems are vulnerable to various attacks, and have been successfully broken. The most serious flaw is that the key stream completely depends on the secret key. That is, the same key stream will be used to encrypt different plain images if the secret key keeps the same. 2.For chaos-based image encryption, the time consumption mainly derives from the floating point arithmetic operation and the quantization arise from the chaotic map iteration. 3.Low dimensional chaotic maps are more vulnerable for cryptanalytic attacks like Known-text attack and chosen-text attack and statistical attacks.

4.Some permutation algorithms like 3-D baker, Cat map and so on have an obvious flaw, the key space is not large enough and the iteration circle is also small.

Next Stage of Planning• VMEI ( Visually Meaningful

Encrypted Image )

Proposed Algorithm

Image Password

Image + Password

Encryption

VMEI

Encryption

VMEI

image

Encryption

VMEI

password

Encryption

Encrypted Password

ConclusionIn this internet world nowadays, the security of images is very important. The security for the digital images has become highly important since the communication by transmitting of digital products over the open network occur very frequently. Image encryption is a technique in which either a pixel is converted to another pixel (value transformation based encryption) or replaced by other pixel in same image (position permutation) or visual transformation based algorithm (Image on image i.e. image as a key, or watermark, based encryption). Here we surveyed some of these algorithms. Each technique has its own suitability area and limitations. Bio-hashing authentication And Encryption Is the future.

Bibliography1) Xingyuan Wang · Dahai Xu : A novel image encryption scheme using chaos and Langton’s Ant cellular automaton.Nonlinear Dyn (2015) 79:2449–2456

2) Wun-She Yap · Raphael C.-W. Phan ·Wei-Chuen Yau · Swee-Huay Heng : Cryptanalysis of a new image alternate encryption algorithm based on chaotic map. Nonlinear Dyn (2015) 80:1483–1491

3) NanrunZhou HaolinLi, Di Wang, Shumin Pan, Zhihong Zhou : Image compression and encryption scheme based on 2D compressive sensing and fractional Mellin transform. Optics Communications343(2015)10–21

4) Xiao-Wei Li, Seok-Tae Kim, In-Kwon Lee : 3D image encoding in FT domain based on CGII algorithm. Applied Mathematical Modelling 39 (2015) 3899–3912 5) Wikipedia. http://en.wikipedia.org/wiki/Cellular_automaton

6) Lahieb Mohammed Jawad · Ghazali Sulong : Chaotic map-embedded Blowfish algorithm for security enhancement of colour image encryption. Nonlinear Dyn (2015) 81:2079–2093 DOI 10.1007/s11071-015-2127-9