PTT數位生活區 / Prob_Solve (計算數學 Problem Solving)

[請益] 同代像演算法加密

看板Prob_Solve (計算數學 Problem Solving)作者freeman0220 (wiki)時間13年前 (2011/12/25 23:52)推噓0(0推 0噓 0→)

留言0則, 0人參與討論串1/1

這裡有一些數學式是有關於同代像加密法的我的數學能力和程式能力並不是很強... 所以我不知道該怎麼讓他從數學式轉成程式碼他不算是作業，只是老師要我們想看看我還是不清楚要怎麼寫... 請版內高手幫我解答一下... Let p = 7, q = 11, then n = 77. For simplicity, let l = 2, that is, each plaintext message is split into 2 smaller pieces. Let ri = si = 5, i = 1, 2. Suppose there are two plaintext numbers in Z77: a = 10 and b = 7. It can easily be seen that 7a+b ≡ 0 (mod 77) and 14a + 2b ≡ 0 (mod 77). The scheme runs as follows. Encrypting a: Decompose a into a1 = 4 and a2 = 6. E(a) = ((4 × 5 mod 7, 4 × 5 mod 11), (6 × 5 mod 7, 6 × 5 mod 11)) = ((6, 9), (2, 8)) Encrypting b: Decompose b into b1 = 3 and b2 = 4. E(b) = ((3 × 5 mod 7, 3 × 5 mod 11), (4 × 5 mod 7, 4 × 5 mod 11)) = ((8, 4), (6, 9)) Computing E(7a + b): E(7a + b) = ((7 × 6 + 8, 7 × 9 + 4), (7 × 2 + 6, 7 × 8 + 9)) mod 77 = ((50, 67), (20, 65)) 用C或javascript 都可以謝謝。 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 175.180.67.19