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Zip 2.0 encryption

Does anyone know if there is a crypto provider for the "zip 2.0" format? I believe that "Zip 2.0" is the format used by WinZip. I need to produce encrypted zip files which can be opened by WinZip.Ravi

[228 byte] By [ravisikka] at [2007-9-26 1:39:09]

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# 1

Hi,

You can create ZIP-files using java.util.zip classes (part of standard Java API, not JCE). These classes do not supported encrypted ZIP-files. Which is no big deal, because ZIP-file encryption is not very secure anyway.

Better solution is to encrypt files using JCE and then using Java ZIP-classes to create a ZIP-file containing the encrypted files.

Regards,

Ronald

rjmaas at 2007-6-29 2:27:57 >

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# 2

But then there would be no compression gain after encrypting the file because encrypted files are not compressible. An alternative is to use the DeflatorInputStream to compress the data first and then encrypting it and then adding the data into the zip archive with no compression.

nrlz at 2007-6-29 2:27:57 >

# 3

Hi,Better to compress files first and then encrypt the ZIP-files.Reason: encrypted files have very bad compression ratesRegards,Ronald Maas

rjmaas at 2007-6-29 2:27:57 >

# 4

Which of these solutions solves his problem of being able to create files that can be used by WinZip? Zip encryption may not be secure, but when you're required to support it, that doesn't matter. So, does anyone know of a way to do this?

minton at 2007-6-29 2:27:57 >

# 5

Not very helpful suggestion...

BUT...

Find out the file format, and encrypt the encyptable parts using the encryption methods of ZIP2.0, which you may or may not be able to find out elsewhere (perhaps on the net somewhere).

ie Build your zip file from scratch! Bit of a mission.

Weasel2K at 2007-6-29 2:27:57 >

# 6

I have need to password encypt a zip file so that it can be opened by WinZip or PKZip. f anybody has a solution tothis problem yet, please let me know.

DanielVeilleux at 2007-6-29 2:27:57 >

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