Image 能否在不丢失exif数据的情况下加密PNG？
我一直在研究这个Reddit难题： 而且，该线程中的大多数用户都被难住了。完全公开，我很想赢得这个奖项，但是通过引起人们的注意并寻求帮助，我知道我减少了我的机会，但在这一点上，我更想知道图片上说的是什么Image 能否在不丢失exif数据的情况下加密PNG？,image,encryption,steganography,Image,Encryption,Steganography,我一直在研究这个Reddit难题： 而且，该线程中的大多数用户都被难住了。完全公开，我很想赢得这个奖项，但是通过引起人们的注意并寻求帮助，我知道我减少了我的机会，但在这一点上，我更想知道图片上说的是什么 我们将密码缩小为包含PNG exif数据的文本文件的URL，但当作为PNG打开时，它被破坏了。该PNG是否可以加密或故意破坏，以保存exif数据？最好的方法是什么？请注意，数字字符串和“AK”明确地链接到这条线索，因此我只能假设可能涉及到一个异步密钥，或者是由Arjen Kampf Lenst
我们将密码缩小为包含PNG exif数据的文本文件的URL，但当作为PNG打开时，它被破坏了。该PNG是否可以加密或故意破坏，以保存exif数据？最好的方法是什么？请注意，数字字符串和“AK”明确地链接到这条线索，因此我只能假设可能涉及到一个异步密钥，或者是由Arjen Kampf Lenstra或某个愤怒的孩子首创的标准。当然，使用ImageMagick如下：
# Look at rose image before we start, and its header
identify -verbose rose.jpg
encrypted.pngconvert -comment "Freddy frog" rose.jpg -encipher passphrase.txt encrypted.png
identify -verbose encrypted.png
Image: encrypted.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 70x46+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 3220
Red:
min: 0 (0)
max: 255 (1)
mean: 126.755 (0.497077)
standard deviation: 73.7824 (0.289343)
kurtosis: -1.18047
skewness: 0.0142557
entropy: 0.99254
Green:
min: 0 (0)
max: 255 (1)
mean: 127.937 (0.501712)
standard deviation: 75.0501 (0.294314)
kurtosis: -1.23185
skewness: -0.0233363
entropy: 0.992485
Blue:
min: 0 (0)
max: 255 (1)
mean: 127.594 (0.500368)
standard deviation: 74.64 (0.292706)
kurtosis: -1.22352
skewness: -0.0177342
entropy: 0.992544
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 127.428 (0.499719)
standard deviation: 74.4927 (0.292128)
kurtosis: -1.21239
skewness: -0.00900116
entropy: 0.992523
Rendering intent: Perceptual
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 70x46+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
cipher:mode: CTR
cipher:nonce: d3d57ca43eacb27a9d72b65ef976923e5b761c7aaaee1d1914d1769ca4834488
cipher:type: AES
comment: Freddy frog <--- comment is visible
date:create: 2015-10-04T18:48:43+01:00
date:modify: 2015-10-04T18:48:43+01:00
png:bKGD: chunk was found (see Background color, above)
png:cHRM: chunk was found (see Chromaticity, above)
png:gAMA: gamma=0.45454544 (See Gamma, above)
png:IHDR.bit-depth-orig: 8
png:IHDR.bit_depth: 8
png:IHDR.color-type-orig: 2
png:IHDR.color_type: 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 70, 46
png:sRGB: intent=0 (Perceptual Intent)
png:text: 6 tEXt/zTXt/iTXt chunks were found
signature: 273e3934027f6ffbcf00b3eca7eb0c576d8fd180e87133112ecacd59225986ee
Artifacts:
filename: encrypted.png
verbose: true
Tainted: False
Filesize: 10.1KB
Number pixels: 3.22K
Pixels per second: 3.22EB
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.1-10 Q32 x86_64 2015-10-02 http://www.imagemagick.org
什么意思？它是如何加密的？加密是一种无丢失协议，加密不会导致数据丢失我知道，这是一个谜，图像已损坏，但当EXIF数据作为txt文件查看时，它仍然可见，所以我想知道发生了什么？我认为这是谜团的一部分
identify -verbose encrypted.png
Image: encrypted.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 70x46+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 3220
Red:
min: 0 (0)
max: 255 (1)
mean: 126.755 (0.497077)
standard deviation: 73.7824 (0.289343)
kurtosis: -1.18047
skewness: 0.0142557
entropy: 0.99254
Green:
min: 0 (0)
max: 255 (1)
mean: 127.937 (0.501712)
standard deviation: 75.0501 (0.294314)
kurtosis: -1.23185
skewness: -0.0233363
entropy: 0.992485
Blue:
min: 0 (0)
max: 255 (1)
mean: 127.594 (0.500368)
standard deviation: 74.64 (0.292706)
kurtosis: -1.22352
skewness: -0.0177342
entropy: 0.992544
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 127.428 (0.499719)
standard deviation: 74.4927 (0.292128)
kurtosis: -1.21239
skewness: -0.00900116
entropy: 0.992523
Rendering intent: Perceptual
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 70x46+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
cipher:mode: CTR
cipher:nonce: d3d57ca43eacb27a9d72b65ef976923e5b761c7aaaee1d1914d1769ca4834488
cipher:type: AES
comment: Freddy frog <--- comment is visible
date:create: 2015-10-04T18:48:43+01:00
date:modify: 2015-10-04T18:48:43+01:00
png:bKGD: chunk was found (see Background color, above)
png:cHRM: chunk was found (see Chromaticity, above)
png:gAMA: gamma=0.45454544 (See Gamma, above)
png:IHDR.bit-depth-orig: 8
png:IHDR.bit_depth: 8
png:IHDR.color-type-orig: 2
png:IHDR.color_type: 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 70, 46
png:sRGB: intent=0 (Perceptual Intent)
png:text: 6 tEXt/zTXt/iTXt chunks were found
signature: 273e3934027f6ffbcf00b3eca7eb0c576d8fd180e87133112ecacd59225986ee
Artifacts:
filename: encrypted.png
verbose: true
Tainted: False
Filesize: 10.1KB
Number pixels: 3.22K
Pixels per second: 3.22EB
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.1-10 Q32 x86_64 2015-10-02 http://www.imagemagick.org
convert encrypted.png -decipher passphrase.txt decrypted.jpg