1

1. Password

2. Over view of authentication methods

3) Graphical passwords

3.1) recognition based technique.

3.2) Recall based technique-

○ Pass points

○ cued click point(CCP)

○ persuasive cued click point(PCCP)

○Improved PCCP (IPCCP)

○Comparison between IPCCP and PCCP 2

Most commonly used form of user authentication.

It is used to prove identity or access approval to gain

access to a resource.

Two conflicting requirements of alphanumeric

passwords-

1)Easy to remember

2) hard to guess

Many people tend to ignore second requirement,

which lead to weak passwords. So many solutions

have been proposed one of them is graphical

passwords.3

1) Token Based Authentication :

Example : Smart cards , Key cards , ATM

2) Biomatrics:

Example: Finger print, Iris scan ,face recognition

3) Knowledge based authentication:

Example: picture based passwords , most widely used

authentication techniques..

4

5

Two most commonly used techniques in

picture passwords :

1) Recognition Based Technique:

A user is presented with a set of images ,for authentication he

recognize and identify the images he selected during the

registration stage.

2) Recall Based Technique:

User is asked to reproduce something that he created or selected

earlier during registration.

6

1) Pass points: user click on any place on the image to create

password. In order to be authenticated user must click with in

the tolerances in correct sequence.

Password space: N^K

N= the number of pixels,

K= number of points to be

clicked on

7

8

Click

Point

Values

X-

Cordinat

es

Y-

Cordinat

es

a 2 3

b 3 2

c 5 9

d 6 8

e 9 6

Disadvantage: hotspot problem different users tend to select

similar click points as a part of their passwords. Attackers who

yield the knowledge of these hotspots through harvesting can

build attack dictionaries.

2) Cued click point(CCP): It is designed to reduce hotspot

problem, rather than five click points on a single image it takes

five click points on five different images.

user can select their images only to extent that their click point

determines the next image, as it consist of different images, so

it prevent guessing attacks.

remembering the order of click points is no longer the

requirement of user .

9

10

Picture authentication using cued click points:

modules

User registration

process

Picture selection process

System login process

11

12

13

14

There are two ways for selecting pictures as a password:

15

16

17

18

Disadvantage: Although pattern based attack seems to be

ineffective but hotspot problem remained same.

3)Persuasive technology : technology to motivate and

impact people to behave in a desired manner.

3.1)Persuasive Cued Click Point(PCCP):

● persuasive technology is added to CCP .

● It encourage users to select more secure passwords.

● here images are slightly shaded except for a viewport.

● when users created a password, the images were slightly

shaded except for a randomly positioned viewport. The

viewport is positioned randomly rather than specifically to

avoid known hotspots.

Disadvantage: shoulder surfing problem: watching over

people’s shoulder as they process information. E.g..

Observing keyboard as person typing password like ATM

password. 19

3.2)Improved Persuasive Cued Click Point(IPCCP):

It reduce both hotspot problem and shoulder surfing

problem.

Processing:

●By using x-y coordinates it divide image into blocks.

●Merge the blocks, after merging blur the complete

image.

●Activate only one block to set click points during

registration.

20

● User create the ID and allocate the set of images to

select password.

● It use double click method ,as in first click it take empty

values ,and in second click it take the values.

● Double click method is used to prevent shoulder surfing

problem, as most of the attackers focuses on single click

method.

21

1) USABILITY : measured by success rate and password generation time.

1.1) success rate : Login times for both IPCCP and PCCP

Successful user

password creation

Successful user login

IPCCP 38/40 (95%) 35/40 (87.5%)

PCCP 36/40 (90%) 34/40 (85%)

80

82

84

86

88

90

92

94

96

IPCCP PCCP

successful user passwordcreation

successful user login

22

23

24