| 摘要 |
PURPOSE:To realize cryptographic processing suitable for a digital color picture data by combining three method of retarding an output value of one preceding clock and summing the values, addition of random data and replacement of picture elements over three bands of red, green, blue of a color picture. CONSTITUTION:An original picture 1 is added to a delay data 8 of one preceding block by an exclusive OR 9, a key 2 is used to add it with a random data 3 generated by the key 2 at an exclusive OR 4 and a key 5 is used to generate a transposition able 6 and transposition 7 is applied to replace picture elements over red, green and blue bands of the color picture thereby obtaining a cryptographic picture 10. The cryptographic data is fed back for the cryptographic processing of the succeeding block as the delay data 8 by one block. |
