计算机应用与软件
計算機應用與軟件
계산궤응용여연건
COMPUTER APPLICATIONS AND SOFTWARE
2013年
12期
87-92
,共6页
图像加密%图像恢复%像素坐标置乱%像素值置换%抗剪切攻击%混沌系统%混沌序列%Lorenz序列
圖像加密%圖像恢複%像素坐標置亂%像素值置換%抗剪切攻擊%混沌繫統%混沌序列%Lorenz序列
도상가밀%도상회복%상소좌표치란%상소치치환%항전절공격%혼돈계통%혼돈서렬%Lorenz서렬
Image encryption Image recovery%Pixel coordinate scrambling%Pixel value permutation%Anti-shearing attacks%Chaotic system%Chaotic sequence%Lorenz sequence
为有效保护数字图像的信息，提出一种新的基于三维混沌系统及其改进序列的通用加密算法。首先，根据密钥及数字图像的大小m ×n，产生一个长度为m ×n的三维混沌序列。然后，根据子密钥及图像类型对混沌序列进行改进，使其具有理想的伪随机特性。同时，根据子密钥及图像类型将混沌序列转换为无符号整数序列。最后，对改进后的序列进行排序以生成相应的下标序列，并据此对图像进行像素坐标置乱，同时将无符号整数序列依次与对应的像素值进行异或运算以实现像素值置换。针对恶意剪切/涂鸦攻击，同时提出一种基于邻域相邻像素特性的恢复算法。应用评价指标对加密效果与安全性进行分析。实验结果与理论分析表明，该算法运行效率较高，密钥空间巨大，具有良好的加密效果、统计特性与安全性，且抗剪切/涂鸦攻击等抗干忧能力较强。
為有效保護數字圖像的信息，提齣一種新的基于三維混沌繫統及其改進序列的通用加密算法。首先，根據密鑰及數字圖像的大小m ×n，產生一箇長度為m ×n的三維混沌序列。然後，根據子密鑰及圖像類型對混沌序列進行改進，使其具有理想的偽隨機特性。同時，根據子密鑰及圖像類型將混沌序列轉換為無符號整數序列。最後，對改進後的序列進行排序以生成相應的下標序列，併據此對圖像進行像素坐標置亂，同時將無符號整數序列依次與對應的像素值進行異或運算以實現像素值置換。針對噁意剪切/塗鴉攻擊，同時提齣一種基于鄰域相鄰像素特性的恢複算法。應用評價指標對加密效果與安全性進行分析。實驗結果與理論分析錶明，該算法運行效率較高，密鑰空間巨大，具有良好的加密效果、統計特性與安全性，且抗剪切/塗鴉攻擊等抗榦憂能力較彊。
위유효보호수자도상적신식，제출일충신적기우삼유혼돈계통급기개진서렬적통용가밀산법。수선，근거밀약급수자도상적대소m ×n，산생일개장도위m ×n적삼유혼돈서렬。연후，근거자밀약급도상류형대혼돈서렬진행개진，사기구유이상적위수궤특성。동시，근거자밀약급도상류형장혼돈서렬전환위무부호정수서렬。최후，대개진후적서렬진행배서이생성상응적하표서렬，병거차대도상진행상소좌표치란，동시장무부호정수서렬의차여대응적상소치진행이혹운산이실현상소치치환。침대악의전절/도아공격，동시제출일충기우린역상린상소특성적회복산법。응용평개지표대가밀효과여안전성진행분석。실험결과여이론분석표명，해산법운행효솔교고，밀약공간거대，구유량호적가밀효과、통계특성여안전성，차항전절/도아공격등항간우능력교강。
In order to protect digital image information effectively , a new universal encryption algorithm based on 3D chaotic system and its improved sequences is proposed .Firstly, according to the key and the digital image size m ×n , a 3D chaotic sequence with length of m ×n is generated .Then, the chaotic sequence is improved to possess the ideal pseudo-randomness property according to the sub-key and the type of image.Also according to the sub-key and the type of image , at the same time the chaotic sequence is converted to unsigned integer se-quence.Finally, the improved sequence is sorted for generating the corresponding subscript sequence , and pixel coordinates of the image will be scrambled based on it .Meanwhile , the pixel value permutation is realised by using the XOR operation between the unsigned integer se -quence and the corresponding pixel value in turn .In allusion to the malicious shearing or painting attacks ,a recovery algorithm based on neigh-bouring pixels characteristic is presented simultaneously .The effect of the encryption and security is also analysed by using the evaluation in-dex.Experimental results and theoretical analysis show that the algorithm has high running efficiency , large space of keys , good encryption effect, statistical characteristics and security , it also has strong ability in resisting the shearing or painting attacks and anti-noise as well.
