Being the first in your peer group to pick up a new communications technology isn't much good if it gives you no-one to communicate with.

That's the thinking behind PKWare's PartnerLink scheme, which allows an organisation to buy its multiplatform encrypted-Zip technology, called SecureZip, and then give free copies of the software to its business partners.

PKWare founder Phil Katz invented the Zip standard for data compression in the 1980s, but while Zip has been a huge hit, the RSA-encrypted version that PKWare introduced in 2004 has been rather less successful.

"Our customers said they couldn't use SecureZip outside their companies because their partners didn't have it too," said Todd McLees, PKWare's international operations VP.

So PartnerLink offers a cut-down version of SecureZip called SecureLink which can both read and write encrypted data, but can only send to the partner you got it from. "Other solutions give you free encryption libraries, but they're unsupported, or a free reader, but it can't write," claimed McLees. "SecureLink is read/write and it's fully supported."

He gave the example of a mortgage processing company that needs to exchange information securely with banks. It would simply add SecureZip into the comms process, he said, allowing it to protect data with a pass-phrase, a digital certificate, or both. It could also apply different pass-phrases to the same data going to different recipients.

Of course, the business partner still has to install and test the free software, linking it in with their own systems.

"Implementation remains a hurdle," McLees acknowledged. "But we have found that the biggest hurdle has been getting everyone to agree to the same budget item - and projects don't get off the ground without budget."

The partner scheme has been operating in the US for some weeks now, and McLees said that a few users have already upgraded from SecureLink to the full release, enabling them to use it with their own business partners too.

SecureZip is available for Windows, Unix, Linux and IBM's iSeries and zSeries. Pricing is based on the platform - around £25,000 on Windows Server for example, or £80,000 on a mainframe. McLees said that the partner option adds around 30 percent to the cost of SecureZIP alone, but the cost is independent of the number of partners you distribute it to.