Does the App Store 20MB 3G Download Limit Matter?

Re:Does the App Store 20MB 3G Download Limit Matter? by bshep on Monday December 20, 2010 @10:18AM (#2024514)

I think what they mean is that if your decompressed binary has long chunks of zeroes which compress really well, when it is encrypted (thanks DRM) those long series of zeroes get changed to non-reapeating data and are no longer easily compressible.

Usually: sizeof(compress(data)) <= sizeof(compress(encrypt(data)))

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Re:Does the App Store 20MB 3G Download Limit Matter? by zyb09 on Monday December 20, 2010 @10:33AM (#2024568)

Why not first compressing then encrypting?

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Re:Does the App Store 20MB 3G Download Limit Matter? by lftl on Monday December 20, 2010 @02:32PM (#2025450)

I suppose you might conceivably actually call them "contagious" zeroes rather than contiguous zeroes in that case.

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Re:Does the App Store 20MB 3G Download Limit Matter? by gst on Monday December 20, 2010 @10:54AM (#2024642)

You can't really compress encrypted data. If it's encrypted it looks more or less like random data. So any encryption is very likely to result in a (minor) size increase, when compared to the original.

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Re:Does the App Store 20MB 3G Download Limit Matter? by bshep on Monday December 20, 2010 @11:17AM (#2024723)

That's what I was trying to say in my comment.

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