A common functionality of many location-based social networking applications is a location sharing service that allows a group of friends to share their locations. With a potentially un-trusted server, such a location sharing service may threaten the privacy of users. Existing solutions for Privacy-Preserving Location Sharing Services (PPLSS) require a trusted third party that has access to the exact location of all users in the system or rely on expensive algorithms or protocols in terms of computational or communication overhead. Other solutions can only provide approximate query answers. To overcome these limitations, we propose a new encryption notion, called Order-Retrievable Encryption (ORE), for PPLSS for social networking applications. The distinguishing characteristics of our PPLSS are that it allows a group of friends to share their exact locations without the need of any third party or leaking any location information to any server or users outside the group, achieves low computational and communication cost by allowing users to receive the exact location of their friends without requiring any direct communication between users or multiple rounds of communication between a user and a server, provides efficient query processing by designing an index structure for our ORE scheme, supports dynamic location updates, and provides personalized privacy protection within a group of friends by specifying a maximum distance where a user is willing to be located by his/her friends. Experimental results show that the computational and communication cost of our PPLSS is much better than the state-of-the-art solution.

1. Privacy-Preserving Location Sharing Services
For Social Networks
ABSTRACT:
A common functionality of many location-based social networking
applications is a location sharing service that allows a group of friends to
share their locations. With a potentially un-trusted server, such a
location sharing service may threaten the privacy of users. Existing
solutions for Privacy-Preserving Location Sharing Services (PPLSS)
require a trusted third party that has access to the exact location of all
users in the system or rely on expensive algorithms or protocols in terms
of computational or communication overhead. Other solutions can only
provide approximate query answers. To overcome these limitations, we
propose a new encryption notion, called Order-Retrievable Encryption
(ORE), for PPLSS for social networking applications. The
distinguishing characteristics of our PPLSS are that it allows a group of
friends to share their exact locations without the need of any third party
or leaking any location information to any server or users outside the
group, achieves low computational and communication cost by
allowing users to receive the exact location of their friends without
requiring any direct communication between users or multiple rounds of
communication between a user and a server, provides efficient query
processing by designing an index structure for our ORE scheme,
supports dynamic location updates, and provides personalized privacy
protection within a group of friends by specifying a maximum distance
where a user is willing to be located by his/her friends. Experimental
results show that the computational and communication cost of our
PPLSS is much better than the state-of-the-art solution.

2. The privacy preserving location sharing services for social networks can
be demonstrated by our application called LSS.A user is having a group
of friends every friend is updating his location from which the user can
retrieve the location of the friend and send him message. But Sharing
must be private it should not known to the third party. So here the friend
is sharing the location encrypted. The encryption is carried on using a
password. Without the password the location cannot be decrypted. The
friend will share the password to the user through email. And the user
has to take the password from the mail to decrypt the location of his
friend and know the distance and route between him and his friend. Then
he can send message to the friend through two options they are through
face book or SMS. Thus the privacy preserving is shown in our project.
The project consists of three modules. They are:
 Sharing location.
 Sharing password
 Finding friends.
 Where I am?
The friends can update the location in the sharing location module to the
user and then have to share the password in the sharing password
module through the email service. The user can find the friends based on
the location. On choosing the location the group of friends in that
location will be displayed. By choosing the friend the friend details will
be displayed which will be in the form of encrypted type. The user has to
get the password from the email and has to decrypt the location. And by
giving the user location the route and the distance between the user and
his friend will be displayed .The user can send message to his friend
either with face book or through message.

3. EXISTING SYSTEM:
Existing location-based social networking systems with location sharing
services rely on a central server which receives location information
from all users in the system. The problem with this approach is that the
central server can generate a detailed movement profile of each user
(e.g., the location, time and frequency of each place which has been
visited by each user) and that raises privacy concerns. Existing privacy-
preserving location sharing schemes aim to protect the user location
privacy against the central server, but they still allow the server to
provide the user with the necessary services. However, in some existing
schemes, the central server still knows the user’s approximate location.
Other schemes require several messages to be exchanged not only
between the user and the central server but also directly between the user
and the user’s friends, increasing the communication cost and making
those schemes less practical. Other schemes only return approximate
results, making them less useful. Peer-to-peer (P2P) systems, where
users’ devices would directly communicate without an intermediate
server are inherently difficult to realize in mobile phone networks as
they typically make use of NAT (network address translation),
restricting direct communication between devices in the process.
DISADVANTAGE:
 A detailed movement profile of each user such as the location, time
and frequency of each user raises privacy concerns.
 Existing privacy-preserving location sharing schemes aim to
protect the user location privacy, but they still allow the server to
provide the user with the necessary services.
 Increases the communication cost and making those schemes less
practical.
 Only return approximate results, making them less useful.

4.  Revealing both identity and location information to an untreated
party poses threats to a mobile users.
 Lack of accuracy. It is very burden to Users.
 Lot of paper works.
PROPOSED SYSTEM:
Our Privacy-Preserving Location Sharing Services for social
networking systems. In particular, our scheme enables users to
browse their friends’ exact locations within a certain distance without
revealing any information about their locations to any other users or a
social networking service provider. The users send their location
information in encrypted form to the database server according to our
scheme. When a user wants to locate his/her friends in the vicinity,
the user logs onto the application and find the user encrypted location.
The user then recovers the actual location of his/her friend by
decrypting with the password.
ADVANTAGE:
 Secure location privacy.
 Low computational and communication cost.
 Efficient data updates.
 Personalized privacy within a group of friends.

5. MODULES:
The LSS application consists of four modules .They are:
 Sharing location.
 Sharing password
 Finding friends.
 Where I am?
SHARING LOCATION:
The friends will update their location to the friend in this module for
privacy preserving they will share the location with a password
encrypted. The friend will update his location, name, number and
address. On encryption the location of the user will be encrypted.
SHARING PASSWORD:
The password must be shared with the user then only he can know how
to decrypt the friend’s location. So the friend will send the password in a
message to the user through email. Thus the password will be shared
your friend.
FINDING FRIENDS:
In the finding friends module the user will find a list of places and on
choosing the place the list of friends in that location will be shown. And
on choosing the friend name the details of the friends will be displayed
with the encrypted location. To decrypt the location the user has to get
the password which is used by his friend to encrypt the location. The
password is sent to him through email service he has to retrieve the
password and has to use that to decrypt the location. On giving his
current location the distance between him and his friend location will be
displayed with the route and time taken to reach the place.

6. WHERE I AM?
In this module there are two categories they are my location and route.
In the my location category your current location will be displayed and
in the route the distance ,time and route between two places will be
displayed.
SYSTEM SPECIFICATION:
HARDWARE REQUIREMENTS:
 System : Pentium IV 2.4 GHz.
 Hard Disk : 40 GB.
 Floppy Drive : 1.44 Mb.
 Monitor : 14’ Colour Monitor.
 Mouse : Optical Mouse.
 Ram : 512 Mb.
SOFTWARE REQUIREMENTS:
 Operating system : Windows 7 Ultimate.
 Coding Language : Java.
 Front-End : Eclipse.
 Data Base : SQLite Manger.