04-07-2012, 02:59 PM
Design of a robust and secure digital signature scheme for image authentication over wireless channels
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Abstract:
The introduction of 3G wireless communication systems, together with the invasive distribution of
digital images and the growing concern on their originality triggers an emergent need of authenticating
images received by unreliable channels, such as public Internet and wireless networks. To meet this need, a
content-based image authentication scheme that is suitable for an insecure network and robust to
transmission errors is proposed. The proposed scheme exploits the scalability of a structural digital signature
in order to achieve a good trade off between security and image transfer for networked image applications.
Introduction
Recent advances in networking and digital media
technologies have created a large number of networked
multimedia applications. Those applications are often
deployed in a distributed network environment that makes
multimedia contents vulnerable to privacy and malicious
attacks. For insecure environments, it is possible for an
enemy to tamper with images during transmission. To
guarantee trustworthiness, image authentication techniques
have emerged to confirm content integrity and prevent
forgery. These techniques are required to be robust against
normal image processing and transmission errors, while
being able to detect malevolent tampering on the image
[1]. Such authentication techniques have wide applicability
in law, commerce, journalism and national defence.
General framework and prior art
Fig. 1 shows the brief diagram of a semi-fragile signature
used for image authentication [1]. There are two main
problems in this diagram. One is that the size of the
generated signature is proportional to the size of the
content and it makes the signing very time consuming;
the other is that the basis of authentication is the correlation
between feature sets and not bit-bit comparison that could
cause some security problems.
Wireless image authentication scheme
As discussed in Section 1, authenticating an image over lossy
wireless channels has its limits and drawbacks. Traditionally,
security is viewed as an independent feature with little or no
relation to the remaining data communication tasks and,
thus, state-of-the-art authentication algorithms are
insensitive to the physical nature of the wireless medium.
In this section, a modified wireless image authentication
scheme has been proposed. This scheme based on robust
digital signatures generated from a secret wavelet transform
of the reconstructed degraded images via an error
concealment technique.
Conclusion
In this paper, a modified digital signature scheme for image
authentication has been proposed. Content-dependent
structural image features and wavelet filter parameterisation
are incorporated into the traditional crypto signature
scheme to enhance the system robustness and security.
Because the proposed scheme does not require any
computational overhead, it is especially suited for wireless
authentication systems and other real-time applications.