International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
Implementation of Online Signature Verification by
Slope Calculation Method
1
A.P.Malode, 2Dr.P.T.Karule
1
Lecturer, Shri Datta Meghe Polytechnic,Nagpur Maharashtra ,India,
apmalode@gmail.com
2
Professor, Yashwantrao chavan college of engineering, Wanadongri, Nagpur ,Maharashtra ,India,
ptkarule@rediffmail.com
ABSTRACT
In this paper we have discussed on the implementation of the online signature verifier using the advanced RISC processor.
The circuit is wired around the Atmel’s AVR microcontroller .We also developed the algorithm based on slop calculation
method. In that the signatures are generated & stored in the permanent memory in the form of look up table. During runtime,
the signatures are again generated in real time and are compared to the stored, expected signatures. If disagreement occurs,
the occurrence of an error is detected & reported..
Keywords: Signature, RISC,AVR, slop calculation, Online array
1. INTRODUCTION
Signature is socially accepted authentication method & is widely used as proof of identity in our daily life. Depending on
the format of input information, automatic signature verification can be classified into two categories
a) Online signature verification
b) Offline signature verification
2. FEATURES
In this algorithm, we take advantage of the online registration data to recover writing trajectory of an offline input
signature & make verification decision based on the
3. BLOCK DIAGRAM OF THE SYSTEM
Touch
screen
A/D converter
Processor
Display
Database in
memory
Figure1: Block diagram of online signature verifier
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
In this system touch screen is used as input device. It is used to sense the signatures which are in the form of
analog signals. These signals are converted into digital signal by using analog to digital converter. After processing,
Microcontroller unit stored the data (digital form of signature) in the memory & the corresponding message i.e.
“signature registered” will be displayed on the LCD display. Digital forms of signatures are stored in the form of array.
When same signature comes on the touch screen, the same process will be repeated. Microcontroller unit will verify the
signature with the database signatures & if the signature matches with corresponding signature of database, the message
“signature correct” will be displayed on the display. If the signature not matches with the database, the message
“signature incorrect” will be displayed on the display
4. CIRCUIT DIAGRAM OF THE SIGNATURE VERIFIER
+Vcc
+Vcc
1 3
RS232
4 5
2
11
12
6
9 10 31
PA0
PA1
RXD
PA2
TXD
PA3
Resistive
Touch
Screen
(Input)
Atmega-16
PB
LCD
D7-D0
RS RW EN
1
2
3
4
SDA
SCL
24512
PD4
PD3
11
PD0
PD1
PD2
32
Figure 2: Circuit diagram of signature verifier
Above circuit diagram of signature verifier is wired around Atmel‟s AVR Atmega16. Resistive type touch
screen is used as an input device. Resistive touch screen are so named because they are basically resistive voltage
dividers. The four wires of the touch screen namely x+, x-, y+, y- are connected with the port A pins . LCD 16×2 display
is used as output device ,the data lines D7-D0 of LCD are connected with the port B, control signals RS,R/W,EN are
connected with the PD0,PD1,PD2 pins of the AVR microcontroller respectively. For storing additional database the
additional memory, serial EEPROM (IC 24C512) is connected. The I2C protocol is used to perform the data transfer
between the AVR microcontroller & serial EEPROM. The AVR microcontroller communicates with the other processor
like PC through serial port using RS232 converter. Program can be burn in the microcontroller via serial port.
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
5. FLOWCHART
The system will work in two modes namely registration mode & verification mode. In registration mode the
algorithm will store the signature in EEPROM in the form of array. The array present in EEPROM is called as the
registration array. For the n no. of signatures the n no. of arrays are required. In verification mode algorithm will store
the signature in RAM in the form of array. The array present in RAM is called as online array.
5.1 Data Base Management
The output of the A/D converter is a binary data of the analog signature. By using algorithm, Slopes of the
consecutive coordinates of the signature is calculated, then each slope is converted into the sample .Each sample consists
of 8 bit data .for given signature, 100 samples are generated. So the look up table of 100 samples is created in the
EEPROM memory for the one given signature .Data base is required for comparing two signature samples. The number
of memory locations required for storing the different encoded signatures.
5.2 Flowchart of Signature Registration
Start
Initialization
Taking input from
touch screen
A/D conversion of
signature data
Wait for 5 sec
Slope calculation
Conversion of each
slope in samples
Storing all samples
in array of EEPROM
Stop
Figure 3: Flowchart of signature registration
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
5.3 Flowcharts of Signature Sensing & Verification
A
Start
Adding differences
D1+D2+……+Dn = SUM
Initialization
In ideal case SUM=0
Practically SUM=Deviation
Taking input from
touch screen
A/D conversion of
signature data
Deciding threshold as per the
Deviation
Wait for 5 sec
Slope calculation
Is
SUM<Threshold
No
Conversion of each
slope into samples
Yes
Storing all samples in
the form array of
EEPROM
Message
“Sign
correct”
Message
“Sign
incorrect””
”
„
Subtracting samples
Sample1 of EEPROM-Sample1 of
RAM =difference (D)
Difference=00h
Sample n-Sample n = Dn
Stop
A
Figure 4: Flowchart of signature sensing & verification
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
5.4 Data Processing
The processing unit will check the signature with the database signature (sample codes) by using algorithm. The
algorithm will perform the percentage match with the reference (i.e. given coded samples of signature).Depends on the
percentage match or error, system will decide whether it is correct or not & the corresponding message will be display on
the output device.
6. ALGORITHM
Algorithm of the system based on the slope calculation method
(100,100)
Y (0,100)
(26,26)
o
o
(25,25)
X
(0,0)
(100,0)
Figure 5: Signature Model
6.1 Representation of Signature
In the very first stage the algorithm will find the coordinates of the origin (starting point i.e. Xo,Yo).With
reference to the origin algorithm will find the other coordinates of the signature i.e.(X1,Y1),(X2,Y2), (X3,Y3)…….. . (Xn,
Yn). In the second stage the algorithm will calculate the slopes of the consecutive coordinates by using the standard
formula
Slope =
(Y1 – Y0)
(X1 – X0)
Let‟s assume
Origin = (X0, Y0) = (25, 25)
& (X1, Y1) = (26, 26)
The slope will be
Slope = (26-25) / (26-25) =1
Likewise the other slopes are calculated. One sample is generated for one slope.
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
6.2 Technique Used For Signature Registration
Presuming signature time 5 sec for each signature. For each signature, there are 100 samples generated. The size of
each sample is 8 bit.
Sample rate calculated by
Time required for signature
-------------------------------Total no. of samples
5 sec
= ---------100
=
50 m sec
All the samples of signature are stored in EEPROM in the form of look up table (array). It is called as registration array.
In this project 5 arrays are created for 5 different signatures Namely Sign1, Sign2, Sign3, Sign4, and Sign5
Sample1
Sample2
Sample3
Sample1
Sample2
Sample3
Sample1
Sample2
Sample3
Sample1
Sample2
Sample3
Sample1
Sample2
Sample3
-
-
-
-
-
Sample
100
Sample
100
Sample
100
Sample
100
Sample 100
Sign 1
Array
Sign 2
Array
Sign 3
Array
Sign 4
Array
Sign 5
Array
Table 1: Arrays present in EEPROM database
6.3 Technique used for signature sensing & verification
For online verification of signatures, again 100 samples created for each signature. At this stage the temporary look
up table is created for storing all the samples in RAM memory in the form of array, it is called as online array.
In this technique, initially sample1 (8 bit) of online array is subtracted from sample 1 of registration array. Then we
get difference between two samples.
Like that all the samples of online array are subtracted from the corresponding samples of registration array.
Ultimately we get all the differences
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
Sample no.
1 of sign1
array
present in
EEPROM
Sample no. 1
of10010000
array
Eg.
present in
X1
Y1
RAM
Eg. 10010000
Eg. 10010000
Sample no.
100 of sign1
array
present in
EEPROM
X100
Eg.00001111
Difference
no.1
D1
Eg.00000000
Sample no.
100 of array
present in
RAM
Difference
no. 100
Y100
D100
Eg.00001111
Eg.00000000
Figure 6: Subtracting samples from arrays & obtaining differences
Finally added all the differences & summation is stored in the variable named “SUM”. If all differences are zero, the
content of variable SUM is zero.In ideal case the differences should be zero. The content of variable SUM will be zero.
We conclude that the sample matches with their corresponding samples.
But practically the differences are non zero. We got some deviation. Hence the content of variable “sum” is non zero
value. At this stage the threshold is fixed .if the sum is less than the threshold, we conclude that the current signature
matches with the database signature & displayed the message “correct sign”. If the deviation more than threshold,
signature not matches with the database signature. Then we displayed the message “incorrect sign”
Difference
No.1 (D1)
(D1)
Difference
No.2 (D2)
(D1)
Difference
No.100 (D100)
(D1)
SUM
Organized By: GNI Nagpur, India
Figure 7: Summations of all differences
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
Ideally SUM=0, But practically SUM≠0
If SUM≤ Threshold, then result= correct sign
If SUM> Threshold, then result= incorrect sign
Experimental study
The experimental study of the signature verifier has done on the simulator named „Proteus‟. In which 5 switches are
connected for registration of the 5 different signatures. Also we have designed & fabricate the prototype of the signature
verifier.
VCC
U1(PA1/ADC1)
(A)
A
B
RV1
C
RV2
D
U1
GND
1k
LCD1
13
12
D0
D1
D2
D3
D4
D5
D6
D7
7
8
9
10
11
12
13
14
RS
RW
E
4
5
6
VSS
VDD
VEE
LM016L
1
2
3
9
40
39
38
37
36
35
34
33
1
2
3
4
5
6
7
8
RESET
XTAL1
XTAL2
PA0/ADC0
PA1/ADC1
PA2/ADC2
PA3/ADC3
PA4/ADC4
PA5/ADC5
PA6/ADC6
PA7/ADC7
PB0/XCK/T0
PB1/T1
PB2/INT2/AIN0
PB3/OC0/AIN1
PB4/SS
PB5/MOSI
PB6/MISO
PB7/SCK
PC0/SCL
PC1/SDA
PC2/TCK
PC3/TMS
PC4/TDO
PC5/TDI
PC6/TOSC1
PC7/TOSC2
PD0/RXD
PD1/TXD
PD2/INT0
PD3/INT1
PD4/OC1B
PD5/OC1A
PD6/ICP
PD7/OC2
AVCC
AREF
22
23
24
25
26
27
28
29
GND
14
15
16
17
18
19
20
21
30
32
VCC
1k
ATMEGA16
Figure 8: Experimental study on Proteus software
References
[1]
[2]
[3]
[4]
[5]
Yasser Sedaghat, Seyed Ghassem Miremadi, Mahdi Fazeli Dependable Systems Laboratory (DSL) Sharif
University of Technology, Tehran, Iran “Offline Signature Verification Using Online Handwriting
Registration”, 2006 IEEE
K. Wilken and J.P. Shen, “Continuous signature monitoring: low-cost concurrent detection of processor
control errors,” IEEE Trans. on Computer-Aided Design of Integrated Circuits and Systems, Vol. 9, Issue 6,
June 1990, pp. 629-641.
Yu Qiao, Jianzhuang Liu ,Department of Information Engineering The Chinese University of Hong Kong “A
Software-Based Error Detection Technique Using Encoded Signatures”, ©2007 IEEE
H. Madeira and J. G. Silvia, “On-line signature learning and checking”, in Dependable Computing for Critical
Applications 2, J. F. Schlichting and R. D. Schlichting, Eds: Springer-Verlag, 1992, pp. 395–420
Henrique Madeira, Jose Camoes, and Joao Gabriel Silva Department of Electrical Engineerin University of
Coimbr 3000 Coimbra – Portugal “Signature Verification: A New Concept For Building Simple And
Effective Watchdog Processors”, @1991 IEEE
AUTHOR
Organized By: GNI Nagpur, India
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
ISSN 2319 - 4847
Special Issue for National Conference On Recent Advances in Technology and Management
for Integrated Growth 2013 (RATMIG 2013)
A.P. Malode received the B.E. and M.Tech. Degrees in Electronics Engineering from Rashtrasant Tukdoji
Maharaj Nagpur University in 2001 and 2010, respectively. During 2001-2010, he worked as a capacity design
engineer for development of home & industrial automation products in intellect control systems, Nagpur. Also
he worked as lecturer in Electronics engineering. His area of interest is embedded system, Digital & Analog
system design. Now he is working as a lecturer in Electronics & Communication Department, Shri Datta Meghe
Polytechnic, Nagpur.
Organized By: GNI Nagpur, India