Apple encrypts their free artwork

As of the latest iTMS update, Apple is sending encrypted copies of their artwork to iTunes when you select "Get Album Artwork". The only people who probably noticed anything happened were those who used means other than iTunes 7 to get free artwork from Apple. This seems to only apply to albums released after the October 3, 2006 iTMS update.

A path to a cover that used to look like this:

http://a1.phobos.apple.com/r10/Music/38/39/68/
mzi.xmzzmbsl.600x600-100.jpg?downloadKey2=1160626777_b69d6ec64a43566af002c1ad7e09c9fd

now looks like this:

http://a1.phobos.apple.com/r10/Music/38/39/68/
mzi.xmzzmbsl.
enc.jpg?downloadKey2=1160626777_b69d6ec64a43566af002c1ad7e09c9fd

After downloading the encrypted artwork, it appears that iTunes 7 decodes the image and saves it as usual to an ITC file, unencrypted. What method of encoding is used, I do not yet know.

[update]
Here are test files if anyone wants to join me in exploring this further.

A-encr.jpg - An encrypted cover
MD5: A724F4A5FCB1094C3F5C218BAAA83624

B-decr.itc - The cover after iTunes has decoded it and made it into a .ITC
MD5: 7D8F9C20D3D32678F406E7DDF7F76B54

C-decr.jpg - The cover changed to a JPG from the unencrypted ITC using this method
MD5: AAF11FCB75FF930D7367D74EF166ADCA

The encrypted image is 20 bytes larger than the normal image.

[update 2 - 10/6]
Here is another example cover.

ex2-encr.jpg - Encrypted
MD5: 458FCE8A1EBE960C7583EA6A8FD6AF3B

ex2-decr.jpg - Decrypted
MD5: 998AFC20DAF6A50784447A54D42F2C34

[update 3 - 10/17]
A comment reminded me of a finding I forgot to share.

Any two people's encrypted copies of the same cover will be identical. An encrypted copy of cover X will always be Y no matter who downloads it. To test this, have a friend download an encrypted cover and compare it to your copy of the same encrypted cover. The MD5 hashes should be identical.


5 Oct 06 | +Permalink+ | Comments (36)