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Security Protection of Software Programs by Information Sharing and Authentication Techniques Using Invisible ASCII Control Codes. Authors : I-Shi Lee and Wen-Hsiang Tsai Source : International Journal of Network Security, vol. 10, no. 1, pp. 1-10, 2010
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Security Protection of Software Programs by Information Sharing and Authentication Techniques Using Invisible ASCII Control Codes Authors : I-Shi Lee and Wen-Hsiang Tsai Source : International Journal of Network Security, vol. 10, no. 1, pp. 1-10, 2010 Presenter : Ping-Kun Hsu (許鈵昆) Date : 11/26/2010
Outline • Introduction • ASCII control codes • The proposed method • Experimental result • Conclusions
Introduction • Goals • Information Sharing • Authentication • Related Works • Invisible Character Coding Table • Exclusive-OR
ASCII control codes(1/2) invisible in the comments or characters string of VC++ programs
The proposed method(1/8) • Invisible Character Coding Table
The proposed method(2/8) • Flow Chat ⊕ ⊕ Secret random key Shares Secret program Camouflage programs Invisible Character Coding Table Authentication signs Stego-programs
The proposed method(3/8) • Creating shares from the secret program • Ss:Secret program string • Pk: Camouflage program, , k = 1, 2, … , n • Sk: Camouflage programs string, k = 1, 2, …, n • Y’: The expanded key • Ek: The shares, k = 1, 2, …, n Pk Sk = c1c2c3 … S2 = E S1 S3 Sn-1 Sn Y’ Ss ⊕ ⊕ ⊕ ⊕ ‧‧‧ ⊕ ⊕ ⊕ En-1 E1 En E2 E3 ‧‧‧ E
The proposed method(4/8) • Generating authentication signs • Sk: Camouflage programs string, k = 1 ,2, …, n • Ek: The shares, k = 1, 2, …, n • Ak: The authentication signs, k = 1, 2, … ,n • Y : The secret random key Sk = (ABC)16 =(65 66 67)10 65+66+67 mod 170 = 28 Ek = (DEF)16 =(68 69 70)10 68+69+70 mod 170 = 37 Y = (10101010)2 = (170)10 00011100 00100101 = Ak
The proposed method(5/8) • Encoding and hiding the shares and signs • Ek: The shares, k = 1, 2,…, n • Ak: The authentication signs, k = 1, 2,… , n • Fk: Binary string, k = 1, 2,… , n • Pk: Camouflage program, , k = 1, 2, … , n • Pk’: Stego-programs, k = 1, 2, … , n Fk = Ek || Ak = 01000100 01000101 01000110 00011100 00100101 Invisible character coding table 1D1C1D1C1D1C1D1D1D1C1D1E1C1D1F1C1C1E1D1D Pk Pk’
The proposed method(6/8) • Extracting hidden shares and signs • Ek: The shares, k = 1, 2,…, n • Ak: The authentication signs, k = 1, 2,… , n • Fk’: The extracted character string, k = 1, 2,… , n • Pk: Camouflage program, , k = 1, 2, … , n • Pk’: Stego-programs, k = 1, 2, … , n Pk’ = Pk || Fk’ Fk’ = 1D1C1D1C1D1C1D1D1D1C1D1E1C1D1F1C1C1E1D1D Invisible character coding table 01000100 01000101 01000110 00011100 00100101 Ek Ak
The proposed method(7/8) • Authenticating • Ek: The shares, k = 1, 2,…, n • Ak’: The authentication signs, k = 1, 2,… , n • Pk: Camouflage program, , k = 1, 2, … , n • Sk: Camouflage programs string, k = 1, 2, …, n • Y : The secret random key Ak’ =00011100 00100101 Ak = 00011100 00100101 Pk Sk = c1c2c3 … 65+66+67 mod 170 = 28 68+69+70 mod 170 = 37 Sk = (ABC)16 =(65 66 67)10 Y = (10101010)2 = (170)10 00011100 00100101 = Ak’ Ek = (DEF)16 =(68 69 70)10
The proposed method(8/8) • Recovering the secret program • Ss:Secret program string • Sk: Camouflage programs string, k = 1, 2, …, n • Y’: The expanded key • Ek: The shares, k = 1, 2, …, n = E ⊕ S2 S1 S3 Sn-1 Sn Y’ Ss ⊕ ⊕ ⊕ ‧‧‧ ⊕ ⊕ ⊕ E1 || E2 || E3 || En-1 || En = E ‧‧‧
Conclusions • The proposed method may decrease the doubts of malicious attackers. • The proposed method may be extended to deal with web pages.