Updated WinZip alters Zip format

WinZip 9.0, from the market leader among file-compression utilities, has entered public beta with scheduled release later this year, bringing with it a new .zip format - which means some of its functions will not be compatible with earlier versions or other programs.

If you use the forthcoming WinZip 9.0's latest encryption and compression options, or create larger archives than were previously possible, your .zip files won't be universally readable.

The final version will cost $29, and will be available as a free upgrade for all registered users. Other new features include HTML help and improved dialog boxes.

Almost every PC user can open a .zip file. Dedicated compression programs such as file managers, file viewers, and even Windows XP can handle these compressed archives. When a format is this ubiquitous, changing it, even to make major improvements, is risky for all concerned.

Still, the update provides a few handy new functions.

No change to the .zip format is likely to be as welcome as improved encryption. Using the old standard, a password-protected .zip file was safe from the prying eyes of an average person, but not those of an average hacker.

So WinZip 9.0 supports 128- and 256-bit key AES encryption, that is unlikely to be cracked by anyone. The old password protection is available, as well.

The new beta can also make your archives smaller with the optional "enhanced deflate" compression method. But don't expect miracles. Casual testing shows significant improvements only with files that compressed a great deal to begin with, such as .bmp files. The current WinZip 8.1 can read, but not write, "enhanced deflate" .zip files.

The new version's 64-bit extensions mean you can create archives holding more than 65,535 files and larger than 4GB - assuming you have the hardware resources and desire. Of the three format changes, this one is least likely to cause compatibility problems; few people share 5GB files over the Internet.

WinZip isn't the first company to monkey with the .zip format recently; but its market share makes it significant. PKWare, the corporate heir to the late Phil Katz, inventor of the .zip format, has introduced incompatible options over the years, as well.

In fact, WinZip's enhanced deflate method and 64-bit extensions are based on, and compatible with, recent PKZip upgrades. PKZip added AES encryption earlier this year, but the two implementations are not compatible.

WinZip has posted the encryption spec on its Web site. Unlike PKWare, WinZip will not offer a free vie_pconnect("user=cking the appropriate application.

Will other developers of compression utilities adopt the changes? Representatives of PentaWare, maker of PentaZip and Aladdin Systems, which markets Stuff-It, confirmed that they were working to make their products compatible with WinZip 9.0. PKWare has not yet decided whether it will support WinZip's encryption.

And what about Microsoft? Windows XP handles .zip files transparently, and less knowledgeable Windows XP users sometimes unzip without even realising they're opening compressed files.

These people may not know why a "compressed folder" refuses to open, if Microsoft does not support WinZip's new format.

Microsoft will only say that it "has nothing to announce at this point."

Whatever happens, it's inevitable that some users will find themselves looking at a .zip file that they can't open.

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Lincoln Spector

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