20-03-2012, 03:37 PM
A NOVEL ERROR-TOLERANT METHOD IN AES FOR SATELLITE IMAGES
aes for satellite images.pdf (Size: 1.42 MB / Downloads: 214)
INTRODUCTION
An Earth observation (EO) satellites are satellites
specifically designed to observe Earth from orbit, similarly
reconnanissance satellites but intended for non-millitary uses
such as environmental monitoring meterology, map making
etc[10] . This Earth Observation satellite takes images on earth
using image sensors. Geostationary Operational
Environmental Satellites, Himawari, Misc ets are some of the
earth observation satellites [11]. Earth Observation satellites
were used more effectively in disaster management support.
Today meterological satellites are widely used to detect and
track severe stroms and to support other wheather-driven
events. However, operational of data from these and other EO
satellites to support management of other types of disasters
(e.g., soil, spills, harmful algae blooms, earthquakes, forest
fires)[12]. Topsat is an EO satellite which is of 110 kg and its
orbit power is of 55w. Security services is much needed to
protect the data from unauthorized access while transmitting
data from satellites.
PROPOSED SYSTEM
To overcome the drawbacks which are shown in the
existing system, this proposed system uses a new fault tolerant
technique based on AES. To address the reliability issues of
AES algorithm and to overcome the SEU. Five modes are used
in AES. They are Cipher block chaining mode (CBC),
PROCEEDINGS OF ICETECT 2011
Electronic code Book mode (ECB), Cipher Feedback Mode
(CFM), Counter mode (CTR) and Output Feedback mode
(OFB).
ADVANCED ENCRYPTION STANDARD AND OUTPUT FEEDBACK MODE
The AES is a symmetric key algorithm, in which both the
sender and the receiver use a single key for encryption and
decryption. AES defines the data block length to 128 bits, and
the key lengths to 128, 192, or 256 bits [3]. It is an iterative
algorithm and each iteration is called a round. The total
number of rounds, Nr, is 10, 12, or 14 when the key length is
128, 192, or 256 bits, respectively. Each round in AES, except
the final round, consists of four transformations: SubBytes,
ShiftRows, MixColumns, and AddRoundKey. The final round
does not have the MixColumns transformation as shown in
. The decryption flow is simply the reverse of
the encryption flow and each operation is the inverse of the
corresponding one in the encryption process.
CONCLUSION
This paper focus the reliability of the AES algorithm for
use on board EO small satellites. And this paper also focuses
the encryption of color image. OFB mode of AES and its
advantages and disadvantages for encryption of satellite
images is discussed in detail. The impact of the propagation
of SEU faults occurring during on-board encryption is
analyzed. In addition, an analysis of the propagation of faults
that occur during transmission due to noise is carried out.