1 Chaotic Generator in Digital Secure Communication 張 書 銘 交通大學應用數學系...

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Chaotic Generator in Digital Secure Communicatio

n

張 書 銘交通大學應用數學系

smchang@math.nctu.edu.tw2008 年 12 月 20 日

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Chaos Secure Communication Chaotic Generator Conclusions

Outline

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Chaos

Chaos is “ mess, disorder, uncontrollable ! ?

Smoke of Cigarette Mike in coffee

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Lorenz strange attractor

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Three planar charged particles

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Three planar charged particles

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Three planar charged particles

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Henon map

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Discrete predator-prey map

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Logistic map

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Secure Communication

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Digital secure communication

Transmitter Receiver

SourceDigital Data

Chaotic Encryption

Unit

AcquireDigital DataCiphertext

Plaintext

Encryption Decryption

ChaoticDecryption

Unit

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Applications - 1

CommunicationCommunication InformationInformation

EntertainmentEntertainmentTransactionTransaction

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Applications - 2

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Chaotic Generator

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Logistic map

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Modified Logistic map

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Properties of MLM

• Chaotic map

• No windows

• Uniform distribution

• Equivalent

• Pseudorandom

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MLM: chaotic map

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MLM: no windows

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MLM: no windows

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MLM: uniform distributionr = 5.9

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MLM: uniform distributionr = 10.8

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MLM: equivalent

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MLM: equivalent

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MLM: pseudorandom

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MLM: pseudorandom

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Conclusions

•Propose Modified Logistic Map (MLM)•Show that MLM is a chaotic map (Devaney's definition)•No windows•Uniform distribution, equivalent•Pseudorandom

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Thank you for your attention!

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Random vs. Chaos

,...,...,, 10 nxxx

,...,...,, 10 nyyy

Identity : 1. Continuous Spectrum

2. Correlation Function :

1nnknk xxC

Random numbers:

Chaotic signals:

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Random vs. Chaos

Observable:

Temporal Average for (1):

Perturbation:

Temporal Average for (2):

rnn Ryfy )(1)1(

:A ractorstrangeatt ,attractor dA dim

r

yyz

rnn

n

)()1( ...

N

iNi az

N 1

1

,)ˆ(ˆ 1 nnn yfy )2( noisen :

N

iNi az

N 1

ˆˆ1

11ˆ difaa nn

3. Stability :

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Random vs. Chaos

Distinction:

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Further

•Based on MLMs, we establish Modified Logistic Hyper-Chaotic System (MLHCS)•Apply MLHCS to develop a symmetric cryptography algorithm•Asymptotic Synchronization of Modified Logistic Hyper-Chaotic System (ASMLHCS)

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Digital secure communication

Transmitter Receiver

SourceDigital Data

MLHCS Encryption

Unit

AcquireDigital DataCiphertext

Plaintext

Encryption Decryption

ASMLHCSDecryption

Unit

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S. M. Chang, M. C. Li and W. W. Lin, Asymptotic synchronization of modified logistic hyper-chaotic systems and its applications. Nonlinear Analysis: Real World Applications, Vol. 10, Issue 2 (2009), pp. 869–880.

S. M. Chang, T. C. Lin and W. W. Lin, Chaotic and Quasiperiodic Motions of Three Planar Charged Particles. Int. J. Bifurcation Chaos, Vol. 11, No. 7 (2001), pp. 1937–1951.

S. L. Chen, S. M. Chang, T. T. Hwang and W. W. Lin, Digital secure-communication using robust hyper-chaotic systems. Int. J. Bifurcation Chaos, Vol. 18, No. 11 (2008), pp. 1–14.

References

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