A turtle shellbased visual secret sharing scheme with

A turtle shell-based visual secret sharing scheme with reversibility and authentication u Source : Multimedia Tools and Applications (2018) 77: 25295 -25310. https: //doi. org/10. 1007/s 11042 -018 -5785 -z u Author: Yanjun Liu; Chin-Chen Chang u Speaker : Lin Li u Date : 2018/10/18 1

Outline u. Introduction u. Related works u. Proposed scheme u. Experimental results u. Conclusions 2

Shamir’s secret sharing scheme(2/3) 4

Shamir’s secret sharing scheme(3/3) 5

Turtle shell (TS) reference matrix(1/2) Elements in the same row should satisfy: Elements in the same column should satisfy: 6

Turtle shell (TS) reference matrix (2/2) 7

…… Original cover image …… …… …… Share 1 Share 2 8

Proposed scheme --Location collision problem Diamond: not included in any chief shell Square: a left edge element of a lower chief shell Circle: an upper back element of a lower chief shell Triangle: a lower back element of an upper chief shell pentagon: a right edge element of an upper chief shell 龜背點，例如（2, 2）、（3, 3） 藏 3位信息，介於[0, 7]； 龜邊點，例如（1, 1），（4, 4, ） 藏 1位信息，即 0或 1。 chief turtle shell MTS(4 l + 2, 4 l) MTS(4 l + 3, 4 l+2)

Proposed scheme --Secret extraction phase 1274<<65, 536 11

Experimental results(1/4) Experimental results of the proposed scheme

Experimental results(2/4) Comparison of visual quality among different VSS schemes

Experimental results(3/4) DR values for different tampered shares Detection Ratio： DR =NTPD/NTP

Experimental results(4/4) Authentication ability under different attacks 15

Conclusions • slightly modified • meaningful shares • complete reversibility • high authentication ability • enhances the visual quality of the shares • outperforms some previously proposed schemes 16

Thanks for your listening！ 17