TSINGHUA SCIENCE AND TECHNOLOGY
ISSNll1007-0214ll01/18llpp225-231
Volume
17,
Number
3,
June
2012
Provably Secure Information Hiding via Short Text
in Social Networking Tools
*
Wei Ren
1,2,**
, Yuliang Liu
1
, Junge Zhao
3
1. School of Computer Science, China University of Geosciences, Wuhan 430074, China;
2. Shandong Provincial Key Laboratory of Computer Networks, Jinan 250014, China;
3. Department of Information Security, Naval University of Engineering, Wuhan 430030, China
Abstract: Utilizing OnLine Short Text (OLST) in social networking tools such as microblogs, instant messag-
ing platforms, and short message service via smart phones has become a routine in daily life. OLST is ap-
pealing for personal covert communication because it can hide information in a very short carrier text, and
this concealment is hard to detect due to the diversity of normal traffic. However, designing appropriate
schemes confronts several challenges: they need to be provably secure, and their performance needs to
maintain high efficiency and handy usability due to the short length of OLST messages. In this paper, we
propose a family of customized schemes known as HiMix, HiCod, HiOpt, and HiPhs for text steganography
in OLST. These schemes are evaluated in terms of their security and their performance with regard to two
metrics that address the particular characteristics of OLST: hiding rate and hiding ease. All proposed
schemes are proved to be at least computationally secure, and their performance in terms of hiding rate and
hiding ease justifies their applicability in social networking tools that utilize OLST.
Key words: information hiding; provable security; text steganography; covert communication
Introduction
The use of OnLine Short Text (OLST) has become
extremely widespread in daily life; certain services,
such as Multimedia Message Service (MMS)
[1]
and
online chat platforms
[2]
, afford users more opportuni-
ties and greater convenience because of their ability to
conceal information.
Microblogs such as Twitter are also important tools
for social networking and the exchange of information;
they can be employed as a secret personal communica-
tion tool for peer-to-peer or peer-to-group exchanges.
Short Message Service (SMS) is a ubiquitous feature
of smart phone communication. Instant Messaging (IM)
platforms such as Google Talk, MSN Messenger, and
the VoIP client Skype are also extremely popular. In
this paper, we explore how to hide information in
OLST, whose importance has increased significantly
due to the pervasiveness of social communication
tools.
Modern steganography usually hides information in
multimedia files such as image, video, and audio
files
[3,4]
. Recently, text steganography, where informa-
tion is hidden in carrier (or cover) texts, has attracted
considerable interest from researchers
[5]
. A cover text
is usually of ordinary length, such as a Microsoft Word
document
[6,7]
. However, OLST is different from cover
texts in terms of information hiding. It has a limited
Received: 2012-04-09; revised: 2012-04-20
**
Supported by the Open Research Fund from the Shandong Provin-
cial Key Laboratory of Computer Networks (No. SDKLCN-2011-
01), the Special Fund for Basic Scientific Research of Central Col-
leges, China University of Geosciences (Wuhan) (No. 110109), an
the National Natural Science Foundation of China (No. 61170217)
**
To whom correspondence should be addressed.
E-mail: weirencs@cug.edu.cn