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I use winrar to protect a file from others reading it. I set a password on the archive and use a 5-digit password. Is this secure or not?

When I want to read it, I extract the archive,read it and then delete the archive normally. It is a text file. How can I make sure that the text file that I unrar can not cannot be made readable again using some program.

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migrated from Mar 4 '11 at 13:29

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5 decimal digits is much too short. – CodesInChaos Mar 4 '11 at 13:34

I would make three comments:

1) A 5 digit password isn't nearly long enough to prevent brute-forcing of the password for decryption. If you chose a significantly complex pass phrase Winrar's encryption is quite secure. Personally however I would recommend TrueCrypt.

2) Unless you are doing a secure erase the file would be easily recoverable for some time after you delete it.

3) The question was a little bit difficult to follow due to poor grammar.

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I think there are evaral application which can crack rar or zip files easyly by brute foce method or using dictionaries. ex:-

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Password protection of archives is usually not very strong (I know of pwds in zip and rar is probaly not very much different).

Also 'normal delete' is unsave. It can often be reverted with undelete.

Suggest encrypt with pgp and some kind of secure delete.

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Rar is much slower to brute-force than zip. And I'm not aware of any better attacks than just trying passwords using dictionaries or brute-force. – CodesInChaos Mar 4 '11 at 13:33

It would be easy for brute-force password crackers if you will be telling that my password is 5 digits long. But without knowing length it would be little hard to crack. You can increase number of permutation by adding special characters, and normal characters both capital and small letters.

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