Free software that encrypts your IM communicationFor those who\u2019ve come to rely on it, instant messaging makes e-mail look old and creaky.You\u2019ve probably sent off important e-mail messages when time was tight. You sat and hoped your intended recipient was at the keyboard and in the mood to respond. You repeatedly clicked Send\/Receive, muttering \u201cHurry up!\u201d all the while.The trouble is, most IM software is vulnerable. Using easily downloaded \u201csniffer\u201d tools, anybody can eavesdrop on unencrypted IM conversations. Major software vendors are now selling enterprise-grade IM applications that rigorously secure and archive IM communication. Business-class IM software blocks access to peer-to-peer file-sharing networks, encrypts messages in transit and saves a copy of all IM traffic.AOL, Microsoft or Yahoo all offer encryption on their corporate-class IM software, but the vast majority of small-business people use the entry-level freebie versions. The good news is there are a couple of free tools that let you encrypt your IM traffic.A company called\u00a0AIM Encrypt\u00a0offers a free encryption certificate for users of AOL Instant Messenger (AIM). If you use AIM and you\u2019re cheap like me, this certificate is an option worth considering. It only encrypts IMs if both parties have the certification \u2013 but then, that\u2019s true of any encryption.Zone Labs recently released an upgrade of\u00a0IMsecure, the company\u2019s IM-encryption application that\u2019s aimed at home users and small businesses. IMsecure works with IM from any of the three major services mentioned above, and other smaller players as well, including GAIM (the multiprotocol IM client for Linux, BSD, MacOS X, and Windows) and Cerulean Studios\u2019 Trillian. The free personal version covers only one computer, but so what? Have everybody on your Buddy List install it.\u00a0Keep in mind that IMsecure has inherent limitations. Both sender and recipient must install it, for starters. And the software encrypts messages only during transmission, so it won\u2019t protect your information if a hacker has planted keystroke-logging software in your PC. Finally, it won\u2019t slow the influx of \u201cspim,\u201d the bastard offspring of spam and IM.The Pro version, which costs $149.95 per year for 10 users, adds several nice features, in particular a spim-blocker and a security log, but it might be overkill for some small businesses.