JPEG Image Encryption by Shuffling DCT Coefficients in Defined Block

This paper proposes the Coefficients Shuffling in Defined Block (CSDB) JPEG image encryption algorithm, which encrypts the quantized DCT coefficients. CSDB algorithm mainly decomposes the DC coefficients and shuffles the decomposed DC coefficients and AC coefficients during all defined block. The experimental results demonstrate that the suggested JPEG image encryption algorithm can resist the knowing plain-image attack and NZCA attack.