27-08-2014, 10:27 AM
Three-Dimensional Password for More
Secure Authentication
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Abstract
—Current authentication systems suffer from many
weaknesses. Textual passwords are commonly used; however,
users do not follow their requirements. Users tend to choose
meaningful words from dictionaries, which make textual passwords easy to break and vulnerable to dictionary or brute force
attacks. Many available graphical passwords have a password
space that is less than or equal to the textual password space.
Smart cards or tokens can be stolen. Many biometric authentications have been proposed; however, users tend to resist using
biometrics because of their intrusiveness and the effect on their
privacy. Moreover, biometrics cannot be revoked. In this paper,
we present and evaluate our contribution, i.e., the 3-D password The 3-D password is a multifactor authentication scheme. To be
authenticated, we present a 3-D virtual environment where the
user navigates and interacts with various objects. The sequence
of actions and interactions toward the objects inside the 3-D environment constructs the user’s 3-D password. The 3-D password
can combine most existing authentication schemes such as textual
passwords, graphical passwords, and various types of biometrics
into a 3-D virtual environment. The design of the 3-D virtual
environment and the type of objects selected determine the 3-D
password key space
I. INTRODUCTION
T HE DRAMATIC increase of computer usage has given
rise to many security concerns. One major security concern is authentication, which is the process of validating who
you are to whom you claimed to be. In general, human authentication techniques can be classified as knowledge based (what
you know), token based (what you have), and biometrics (what
you are).
Knowledge-based authentication can be further divided into
two categories as follows: 1) recall based and 2) recognition
based [1]. Recall-based techniques require the user to repeat
or reproduce a secret that the user created before. Recognitionbased techniques require the user to identify and recognize the
secret, or part of it, that the user selected before [1]. One of
the most common recall-based authentication schemes used in
the computer world is textual passwords. One major drawback
of the textual password is its two conflicting requirements: theselection of passwords that are easy to remember and, at the
same time, are hard to guess.: 25% of the passwords were guessed by
using a small yet well-formed dictionary of 3 × 106 words.
Furthermore, 21% of the passwords were guessed in the first
week and 368 passwords were guessed within the first 15 min.
Klein [2] stated that by looking at these results in a system with
about 50 accounts, the first account can be guessed in 2 min
and 5–15 accounts can be guessed in the first day. Klein [2]
showed that even though the full textual password space for
eight-character passwords consisting of letters and numbers is
almost 2 × 1014 possible passwords, it is easy to crack 25% of
the passwords by using only a small subset of the full password
space. It is important to note that Klein’s experiment was in
1990 when the processing capabilities, memory, networking,
and other resources were very limited compared to today’s
technology.
Many authentication systems, particularly in banking, require not only what the user knows but also what the
user possesses (token-based systems). However, many reports
[3]–[5] have shown that tokens are vulnerable to fraud, loss, or
theft by using simple techniques.Graphical passwords can be divided into two categories as
follows: 1) recognition based and 2) recall based [1]. Various graphical password schemes have been proposed [6]–[8],
[10]–[12]. Graphical passwords are based on the idea that users
can recall and recognize pictures better than words. However,
some of the graphical password schemes require a long time
to be performed. Moreover, most of the graphical passwords
can be easily observed or recorded while the legitimate user
is performing the graphical password; thus, it is vulnerable to
shoulder surfing attacks. Currently, most graphical passwords
are still in their research phase and require more enhancements
and usability studies to deploy them in the market.Each biometric recognition scheme has its
advantages and disadvantages based on several factors such as
consistency, uniqueness, and acceptability. One of the main
drawbacks of applying biometrics is its intrusiveness upon
a user’s personal characteristic. Moreover, retina biometrical
recognition schemes require the user to willingly subject their
eyes to a low-intensity infrared light. In addition, most biomeric systems require a special scanning device to authenticate
users, which is not applicable for remote and Internet users.
II. RELATED WORKS
Many graphical password schemes have been proposed
[6]–[8], [10]–[12]. Blonder [6] introduced the first graphical
password schema. Blonder’s idea of graphical passwords is that
by having a predetermined image, the user can select or touch
regions of the image causing the sequence and the location of
the touches to construct the user’s graphical password. After
Blonder [6], the notion of graphical passwords was developed.
Many graphical password schemes have been proposed. Existing graphical passwords can be categorized into two categories
as follows: 1) recall based and 2) recognition based [1].
Dhamija and Perrig [7] proposed Déjà Vu, which is a
recognition-based graphical password system that authenticates
users by choosing portfolios among decoy portfolios. These
portfolios are art randomized portfolios. Each image is derived
from an 8-B seed. Therefore, an authentication server does
not need to store the whole image; it simply needs to store
the 8-B seed. Another recognition-based graphical password
is Passfaces [8]. Passfaces simply works by having the user
select a subgroup of k faces from a group of n faces. For
authentication, the system shows m faces and one of the faces
belongs to the subgroup k. The user has to do the selection
many times to complete the authentication process. Another
scheme is the Story scheme [9], which requires the selection of
pictures of objects (people, cars, foods, airplanes, sightseeing,
etc.) to form a story line. Davis et al. [9] concluded that the user’s choices in Passfaces and in the Story scheme result in
a password space that is far less than the theoretical entropy.
Therefore, it leads to an insecure authentication scheme.
The graphical password schema of Blonder [6] is considered
to be recall based since the user must remember selection locations. Moreover, PassPoint [10]–[12] is a recall-based graphical
password schema, where a background picture is presented and
the user is free to select any point on the picture as the user’s
password (user’s PassPoint). Draw A Secret (DAS), which is
a recall-based graphical password schema and introduced by
Jermyn et al. [13], is simply a grid in which the user creates a
drawing. The user’s drawings, which consist of strokes, are considered to be the user’s password. The size and the complexity
of the grid affect the probable password space. Larger grid sizes
increase the full password space. However, there are limitations
in grid complexity due to human error. It becomes very hard
to recall where the drawing started and ended and where the
middle points were if we have very large grid sizes.
II. RELATED WORKS
Many graphical password schemes have been proposed
[6]–[8], [10]–[12]. Blonder [6] introduced the first graphical
password schema. Blonder’s idea of graphical passwords is that
by having a predetermined image, the user can select or touch
regions of the image causing the sequence and the location of
the touches to construct the user’s graphical password. After
Blonder [6], the notion of graphical passwords was developed.
Many graphical password schemes have been proposed. Exist ing graphical passwords can be categorized into two categories
as follows: 1) recall based and 2) recognition based [1].
Dhamija and Perrig [7] proposed Déjà Vu, which is a
recognition-based graphical password system that authenticates
users by choosing portfolios among decoy portfolios. These
portfolios are art randomized portfolios. Each image is derived
from an 8-B seed. Therefore, an authentication server does
not need to store the whole image; it simply needs to store
the 8-B seed. Another recognition-based graphical password
is Passfaces [8]. Passfaces simply works by having the user
select a subgroup of k faces from a group of n faces. For
authentication, the system shows m faces and one of the faces
belongs to the subgroup k. The user has to do the selection
many times to complete the authentication process. Another
scheme is the Story scheme [9], which requires the selection of
pictures of objects (people, cars, foods, airplanes, sightseeing,
etc.) to form a story line. Davis et al. [9] concluded that the user’s choices in Passfaces and in the Story scheme result in
a password space that is far less than the theoretical entropy.
Therefore, it leads to an insecure authentication scheme.
The graphical password schema of Blonder [6] is considered
to be recall based since the user must remember selection locations. Moreover, PassPoint [10]–[12] is a recall-based graphical
password schema, where a background picture is presented and
the user is free to select any point on the picture as the user’s
password (user’s PassPoint). Draw A Secret (DAS), which is
a recall-based graphical password schema and introduced by
Jermyn et al. [13], is simply a grid in which the user creates a
drawing. The user’s drawings, which consist of strokes, are con
II. RELATED WORKS
Many graphical password schemes have been proposed
[6]–[8], [10]–[12]. Blonder [6] introduced the first graphical
password schema. Blonder’s idea of graphical passwords is that
by having a predetermined image, the user can select or touch
regions of the image causing the sequence and the location of
the touches to construct the user’s graphical password. After
Blonder [6], the notion of graphical passwords was developed.
Many graphical password schemes have been proposed. Exis ing graphical passwords can be categorized into two categories
as follows: 1) recall based and 2) recognition based [1].
Dhamija and Perrig [7] proposed Déjà Vu, which is a
recognition-based graphical password system that authenticates
users by choosing portfolios among decoy portfolios. These
portfolios are art randomized portfolios. Each image is derived
from an 8-B seed. Therefore, an authentication server does
not need to store the whole image; it simply needs to store
the 8-B seed. Another recognition-based graphical password
is Passfaces [8]. Passfaces simply works by having the user
select a subgroup of k faces from a group of n faces. For
authentication, the system shows m faces and one of the faces
belongs to the subgroup k. The user has to do the selection
many times to complete the authentication process. Another
scheme is the Story scheme [9], which requires the selection of
pictures of objects (people, cars, foods, airplanes, sightseeing,
etc.) to form a story line. Davis et al. [9] concluded that the user’s choices in Passfaces and in the Story scheme result in
a password space that is far less than the theoretical entropy.
Therefore, it leads to an insecure authentication scheme.
One important type of authentication is based on who you are
or, in other words, biometrics. Biometric recognition systems
have been exhaustively studied as a way of authentication.
Fingerprints, palmprints, face recognition, voice recognition,
and iris and retina recognition are all different methodologies of biometric recognition systems. However, some human
properties are vulnerable to change from time to time due to
several reasons such as aging, scarring, face makeup, change
of hairstyle, and sickness (change of voice). Moreover, people
tend to resist biometrics for different reasons. Some people
think that keeping a copy of the user’s fingerprints is not
acceptable and is a threat to the user’s privacy. In addition, some
users resist the idea of a low-intensity infrared light or any other
kind of light directed at their eyes, such as in retina recognition
systems. Moreover, biometrics cannot be revoked, which leads
to a dilemma in case the user’s data have been forged. Unlike
other authentication schemes where the user can alter his/her
textual password in case of a stolen password or replace his/her
token if it has been stolen or forged, a user’s biometrics cannot
be revoked
III. 3-D PASSWORD SCHEME
In this section, we present a multifactor authentication
scheme that combines the benefits of various authentication
schemes. We attempted to satisfy the following requirements.
1) The new scheme should not be either recall based or
recognition based only. Instead, the scheme should be
a combination of recall-, recognition-, biometrics-, and
token-based authentication schemes.
2) Users ought to have the freedom to select whether the 3-D
password will be solely recall-, biometrics-, recognition-,
or token-based, or a combination of two schemes or more.
A. 3-D Password Overview
The 3-D password is a multifactor authentication scheme.
The 3-D password presents a 3-D virtual environment containing various virtual objects. The user navigates through this
environment and interacts with the objects. The 3-D password
is simply the combination and the sequence of user interactions
that occur in the 3-D virtual environment. The 3-D password
can combine recognition-, recall-, token-, and biometrics-based
systems into one authentication scheme. This can be done
by designing a 3-D virtual environment that contains objects
that request information to be recalled, information to be
recognized, tokens to be presented, and biometrical data to be
verified. For example, the user can enter the virtual environment
and type something on a computer that exists in (x1, y1, z1)
position, then enter a room that has a fingerprint recognition
device that exists in a position (x2, y2, z2) and provide his/her
fingerprint. Then, the user can go to the virtual garage, open
the car door, and turn on the radio to a specific channel. The
combination and the sequence of the previous actions toward
the specific objects construct the user’s 3-D password.
Virtual objects can be any object that we encounter in real
life. Any obvious actions and interactions toward the real-life
objects can be done in the virtual 3-D environment toward the
virtual objects. Moreover, any user input (such as speaking
in a specific location) in the virtual 3-D environment can be
considered as a part of the 3-D password. We can have the
following objects:
1) a computer with which the user can type;
2) a fingerprint reader that requires the user’s fingerprint;
3) a biometrical recognition device;
4) a paper or a white board that a user can write, sign, or
draw on;
5) an automated teller machine (ATM) that requests a token;
6) a light that can be switched on/off;
7) a television or radio where channels can be selected;
8) a staple that can be punched;
9) a car that can be driven;
10) a book that can be moved from one place to another;
B. 3-D Password Selection and Inputs
Let us consider a 3-D virtual environment space of size G ×
G × G. The 3-D environment space is represented by the co
ordinates (x, y, z) ∈ [1,...,G] × [1,...,G] × [1,...,G]. The
objects are distributed in the 3-D virtual environment with
unique (x, y, z) coordinates. We assume that the user can
navigate into the 3-D virtual environment and interact with
the objects using any input device such as a mouse, keyboard, fingerprint scanner, iris scanner, stylus, card reader, and
microphone. We consider the sequence of those actions and
interactions using the previous input devices as the user’s 3-D
password. For example, consider a user who navigates through
the 3-D virtual environment that consists of an office and a
meeting room. Let us assume that the user is in the virtual office
and the user turns around to the door located in (10, 24, 91) and
opens it. Then, the user closes the door. The user then finds a
computer to the left, which exists in the position (4, 34, 18),
and the user types “FALCON.” Then, the user walks to the
meeting room and picks up a pen located at (10, 24, 80) and
draws only one dot in a paper located in (1, 18, 30), which is the
dot (x, y) coordinate relative to the paper space is (330, 130).
The user then presses the login button. The initial representation
of user actions in the 3-D virtual environment can be recorded
as follows:
(10, 24, 91) Action = Open the office door;
(10, 24, 91) Action = Close the office door;
(4, 34, 18) Action = Typing, “F”;
(4, 34, 18) Action = Typing, “A”;
(4, 34, 18) Action = Typing, “L”;
(4, 34, 18) Action = Typing, “C”;
(4, 34, 18) Action = Typing, “O”;
(4, 34, 18) Action = Typing, “N”;
(10, 24, 80) Action = Pick up the pen;
(1, 18, 80) Action = Drawing, point = (330, 130).
This representation is only an example. The extensive real
representation will not be discussed in this paper. In order for
a legitimate user to be authenticated, the user has to follow the
same sequence and type of actions and interactions toward the
objects for the user’s original 3-D password. Fig. 1 shows a
virtual computer that accepts textual passwords as a part of a
user’s 3-D password.
Three-dimensional virtual environments can be designed to
include any virtual objects. Therefore, the first building block
of the 3-D password system is to design the 3-D virtual
environment and to determine what objects the environmentreal life. Objects used in virtual environments should be
relatively similar in size to real objects (sized to scale).
Possible actions and interactions toward virtual objects
should reflect real-life situations. Object responses should
be realistic. The target should have a 3-D virtual environtions. Moreover, PassPoint [10]–[12] is a recall-based graphical
password schema, where a background picture is presented and
the user is free to select any point on the picture as the user’s
password (user’s PassPoint). Draw A Secret (DAS), which is
a recall-based graphical password schema and introduced by
Jermyn et al. [13], is simply a grid in which the user creates a
drawing. The user’s drawings, which consist of strokes, are considered to be the user’s password. The size and the complexity
of the grid affect the probable password space. Larger grid sizes
increase the full password space. However, there are limitations
in grid complexity due to human error. It becomes very hard
to recall where the drawing started and ended and where the
middle points were if we have very large grid sizes.
One important type of authentication is based on who you are
or, in other words, biometrics. Biometric recognition systems
have been exhaustively studied as a way of authentication.
Fingerprints, palmprints, face recognition, voice recognition,
and iris and retina recognition are all different methodologies of biometric recognition systems. However, some human
properties are vulnerable to change from time to time due to
several reasons such as aging, scarring, face makeup, change
of hairstyle, and sickness (change of voice). Moreover, people
tend to resist biometrics for different reasons. Some people
think that keeping a copy of the user’s fingerprints is not
acceptable and is a threat to the user’s privacy. In addition, some
users resist the idea of a low-intensity infrared light or any other
kind of light directed at their eyes, such as in retina recognition
systems. Moreover, biometrics cannot be revoked, which leads
to a dilemma in case the user’s data have been forged. Unlike
other authentication schemes where the user can alter his/her
textual password in case of a stolen password or replace his/her
token if it has been stolen or forged, a user’s biometrics cannot
be revoked.
Many authentication systems are based on tangible objects
and are referred to as token-based systems. Many token-based
systems are vulnerable to theft and loss; therefore, most tokenIII. 3-D
PASSWORD SCHEME
In this section, we present a multifactor authentication
scheme that combines the benefits of various authentication
schemes. We attempted to satisfy the following requirements.
1) The new scheme should not be either recall based or
recognition based only. Instead, the scheme should be
a combination of recall-, recognition-, biometrics-, and
token-based authentication schemes.
2) Users ought to have the freedom to select whether the 3-D
password will be solely recall-, biometrics-, recognitionThis freedom of selection is necessary because users
are different and they have different requirements. Some
users do not like to carry cards. Some users do not like
to provide biometrical data, and some users have poor
memories. Therefore, to ensure high user acceptability,
the user’s freedom of selection is important.
3) The new scheme should provide secrets that are easy to
remember and very difficult for intruders to guess.
4) The new scheme should provide secrets that are not easy
to write down on paper. Moreover, the scheme secrets
should be difficult to share with others.
5) The new scheme should provide secrets that can be easily
revoked or changed.
Based on the aforementioned requirements, we propose our
contribution, i.e., the 3-D password authentication scheme.
A. 3-D Password Overview
The 3-D password is a multifactor authentication scheme.
The 3-D password presents a 3-D virtual environment containing various virtual objects. The user navigates through this
environment and interacts with the objects. The 3-D password
is simply the combination and the sequence of user interactions
that occur in the 3-D virtual environment. The 3-D password
can combine recognition-, recall-, token-, and biometrics-based
systems into one authentication scheme. This can be done
by designing a 3-D virtual environment that contains objects
that request information to be recalled, information to be
recognized, tokens to be presented, and biometrical data to be
verified. For example, the user can enter the virtual environment
and type something on a computer that exists in (x1, y1, z1)
position, then enter a room that has a fingerprint recognition
device that exists in a position (x2, y2, z2) and provide his/her
fingerprint. Then, the user can go to the virtual garage, open
the car door, and turn on the radio to a specific channel. The
combination and the sequence of the previous actions toward
the specific objects construct the user’s 3-D password.
Virtual objects can be any object that we encounter in real
life. Any obvious actions and interactions toward the real-life
objects can be done in the virtual 3-D environment toward the
virtual objects. Moreover, any user input (such as speaking
in a specific location) in the virtual 3-D environment can be
considered as a part of the 3-D password. We can have the
following objects:
1) a computer with which the user can type;
2) a fingerprint reader that requires the user’s fingerprint;
3) a biometrical recognition device;
4) a paper or a white board that a user can write, sign, or
draw on;
5) an automated teller machine (ATM) that requests a token;
6) a light that can be switched on/off;
7) a television or radio where channels can be selected;
8) a staple that can be punched;
9) a car that can be driven;
10) a book that can be moved from one place to another;
11) any graphical password scheme;
12) any real-life object;
13) any upcoming authentication scheme
C. 3-D Virtual Environment Design Guidelines
Designing a well-studied 3-D virtual environment affects the
usability, effectiveness, and acceptability of a 3-D password
system. Therefore, the first step in building a 3-D password
system is to design a 3-D environment that reflects the administration needs and the security requirements. The design of 3-D
virtual environments should follow these guidelines
1) Real-life similarity: The prospective 3-D virtual environment should reflect what people are used to seeing in real life. Objects used in virtual environments should be
relatively similar in size to real objects (sized to scale).
Possible actions and interactions toward virtual objects
should reflect real-life situations. Object responses should
be realistic.
2) Object uniqueness and distinction: Every virtual object
or item in the 3-D virtual environment is different from
any other virtual object. The uniqueness comes from
the fact that every virtual object has its own attributes
such as position.
3) Three-dimensional virtual environment size: A 3-D virtual environment can depict a city or even the world. On
the other hand, it can depict a space as focused as a single
room or office. The size of a 3-D environment should
be carefully studied. A large 3-D virtual environment
will increase the time required by the user to perform a
3-D password. Moreover, a large 3-D virtual environment
can contain a large number of virtual objects. Therefore,
the probable 3-D password space broadens. However, a
small 3-D virtual environment usually contains only a few
objects, and thus, performing a 3-D password will take
less time.
IV. SECURITY ANALYSIS
To analyze and study how secure a system is, we have to
consider how hard it is for the attacker to break such a system.
A possible measurement is based on the information content of
a password space, which is defined in [13] as “the entropy of
the probability distribution over that space given by the relative
frequencies of the passwords that users actually choose.” We
have seen that textual password space may be relatively large;
however, an attacker might only need a small subset of the full
password space as Klein [2] observed to successfully break
such an authentication system. As a result, it is important to
have a scheme that has a very large possible password space
as one factor for increasing the work required by the attacker
to break the authentication system. Another factor is to find
a scheme that has no previous or existing knowledge of the
A. 3-D Password Space Size
One important factor to determine how difficult it is to
launch an attack on an authentication system is the size of the
password space. To determine the 3-D password space, we have
to count all possible 3-D passwords that have a certain number
of actions, interactions, and inputs toward all objects that exist
in the 3-D virtual environment. We assume that the length of the
3-D password is Lmax, and the probability of the 3-D password
of size greater than Lmax is zero.
B. 3-D Password Distribution Knowledge
Studying the user’s behavior of password selection and
knowing the most probable textual passwords are the key
behind dictionary attacks. Klein [2] used such knowledge toability of usage among users. The question is how has such
information (highly probable passwords) been found and why.
Users tend to choose words that have meaning, such as places,
names, famous people’s names, sports terms, and biological
terminologies. Therefore, finding these different words from the
dictionary is a relatively simple task. Using such knowledge
yields a high success rate for breaking textual passwords. Any
authentication scheme is affected by the knowledge distribution
of the user’s secrets. According to Davis et al. [9], Passfaces
[8] users tend to choose faces that reflect their own taste on
facial attractiveness, race, and gender. Moreover, 10% of male
passwords have been guessed in only two guesses. Another
study [14] about user selection of DAS [13] concluded that
collect a small set of 3 × 106 words that have a high probability of usage among users. The question is how has such
information (highly probable passwords) been found and why.
Users tend to choose words that have meaning, such as places,
names, famous people’s names, sports terms, and biological
terminologies. Therefore, finding these different words from the
dictionary is a relatively simple task. Using such knowledge
yields a high success rate for breaking textual passwords. Any
authentication scheme is affected by the knowledge distribution
of the user’s secrets. According to Davis et al. [9], Passfaces
[8] users tend to choose faces that reflect their own taste on
facial attractiveness, race, and gender. Moreover, 10% of male
passwords have been guessed in only two guesses. Another
study [14] about user selection of DAS [13] concluded that for their secret passwords, users tend to draw things that have
meaning, which simplifies the attacker’s task.
C. Attacks and Countermeasures
To realize and understand how far an authentication scheme
is secure, we have to consider all possible attack methods. We
have to study whether the authentication scheme proposed is
immune against such attacks or not. Moreover, if the proposed
authentication scheme is not immune, we then have to find the
countermeasures that prevent such attacks. In this section, we
try to cover most possible attacks and whether the attack is valid
or not. Moreover, we try to propose countermeasures for such
attacks.
Brute Force Attack: The attacker has to try all possible 3-D
passwords. This kind of attack is very difficult for the following
reasons.
1) Time required to login: The total time needed for a
legitimate user to login may vary from 20 s to 2 min
or more, depending on the number of interactions and
actions, the size of the 3-D virtual environment, and the
type of actions and interactions done by the user as a
3-D password. Therefore, a brute force attack on a 3-D
password is very difficult and time consuming.
2) Cost of attacks: In a 3-D virtual environment that contains
biometric recognition objects and token-based objects,
the attacker has to forge all possible biometric information and forge all the required tokens. The cost of forging
such information is very high; therefore, cracking the
3-D password is more challenging. Moreover, the high
number of possible 3-D password spaces (as shown in
Table I) leaves the attacker with almost no chance of
breaking the 3-D password.
Well-Studied Attack: The attacker tries to find the highest
probable distribution of 3-D passwords. However, to launch
such an attack, the attacker has to acquire knowledge of the
most probable 3-D password distributions. Acquiring such
knowledge is very difficult because the attacker has to study
all the existing authentication schemes that are used in the 3-D
environment. Moreover, acquiring such knowledge may requireforging all existing biometrical data and may require forging
token-based data. In addition, it requires a study of the user’s
selection of objects, or a combination of objects, that the user
will use as a 3-D password. Moreover, a well-studied attack
is very hard to accomplish since the attacker has to perform a
customized attack for every different 3-D virtual environment
design. Every system can be protected by a 3-D password that
is based on a unique 3-D virtual environment. This environment
has a number of objects and types of object responses that differ
from any other 3-D virtual environment. Therefore, a carefully
customized study is required to initialize an effective attack.
V. EXPERIMENTAL RESULTS
We have built an experimental 3-D virtual environment that
contains several objects of two types. The first type of response
is the textual password. The second type of response is requesting graphical passwords. Almost 30 users volunteered to
experiment with the environment. We asked the users to create
their 3-D password and to sign-in using their 3-D password
several times over several days.
A. Experimental Virtual 3-D Environment
In our experiment, we have used Java Open GL to build
the 3-D virtual environment and we have used a 1.80-GHz
Pentium M Centrino machine with 512-MB random access
memory and ATI Mobility Radeon 9600 video card.
The design of the experimental 3-D virtual environment
represents an art gallery that the user can walk through and is
depicted in Fig. 2.
B. User Study
We conducted a user study on 3-D passwords using the
experimental 3-D virtual environments. The study reviewed the
usage of textual passwords and other authentication schemes.
The study covered almost 30 users. The users varied in age, sex,
and education level. Even though it is a small set of users, the
study produced some distinct results [13], [15].
We observed
the following regarding textual passwords, 3-D passwords, and
other authentication schemes.
1) Most users who use textual passwords of 9–12 character
lengths or who use random characters as a password have
only one to three unique passwords.
2) More than 50% of user’s textual passwords are eight
characters or less.
3) Almost 25% of users use meaningful words as their
textual passwords.
4) Almost 75% of users use meaningful words or partially
meaningful words as their textual passwords. In contrast,
only 25% of users use random characters and letters as
textual passwords.
5) Over 40% of users have only one to three unique textual
passwords, and over 90% of users have eight unique
textual passwords or less.
6) Over 90% of users do not change their textual passwords
unless they are required to by the system.
7) Over 95% of users under study have never used any
graphical password scheme as a means of authentication.
8) Most users feel that 3-D passwords have a high
acceptability.
9) Most users believe that there is no threat to personal
privacy by using a 3-D password as an authentication
scheme
VI. CONCLUSION AND FUTURE WORK
There are many authentication schemes in the current state.
Some of them are based on user’s physical and behavioral properties, and some other authentication schemes are based
on user’s knowledge such as textual and graphical passwords. Moreover, there are some other important authentication
schemes that are based on what you have, such as smart cards.
Among the various authentication schemes, textual password
and token-based schemes, or the combination of both, are comtion schemes are vulnerable to certain attacks. Moreover, there
are many authentication schemes that are currently under study
and they may require additional time and effort to be applicable
for commercial use.
The 3-D password is a multifactor authentication scheme that
combines these various authentication schemes into a single
3-D virtual environment. The virtual environment can contain
any existing authentication scheme or even any upcoming
authentication schemes by adding it as a response to actions
performed on an object. Therefore, the resulted password space
becomes very large compared to any existing authentication
schemes.
The design of the 3-D virtual environment, the selections
of objects inside the environment, and the object’s type reflect
the resulted password space.