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One Step Ahead
February 17, 2009, Volume 55, No. 22

One Step Ahead

Another tip in a series provided by the Offices of Information Systems & Computing and Audit, Compliance & Privacy.

Instant Messaging and Penn's Jabber Service

In recent years, more and more people have found Instant Messaging (IM) services from companies like America Online, Google and Microsoft a useful way to communicate and exchange data with other users in a “real time” way that even e-mail does not afford. However, there are dangers and pitfalls to using these mass-market IM channels. As with e-mail, you can’t always be absolutely certain the person you’re swapping messages with is really who he/she claims to be. Another concern is that nearly all these services do not encrypt messages in transit, giving an opportunity for hackers to “sniff” the network and intercept them. Most IM services also permit transfer of files between users, and as with the danger of infected e-mail attachments, this can be leveraged to introduce “malware” into the user’s computer. It’s generally better to not use the major IM services for exchanging sensitive or confidential information, but here are a few tips to make IM use a bit safer:

• As with e-mail attachments, don’t open files you receive via IM unless you’re absolutely sure of the sender’s identity and what the content or purpose of the file is.

• Never transmit sensitive or confidential data on an unencrypted IM channel (see the paragraph on Jabber, below).

• Try not to reveal too much information about yourself in your IM profile, including your choice of “screen name”, e.g. “RoxboroughRon”.

• Make your profile and presence available only to your “buddy list,” and restrict your chat sessions to them as much as possible.

• If you use public, lab or other multi-user computers for IM sessions, do not enable any “automatic login” feature.

If you are a current user of pobox.upenn.edu, the Microsoft Exchange server operated by ISC’s Networking & Telecommunications division, or the PennNet Phone service, you have access to an encrypted IM service using the popular Jabber protocol. In addition to encryption, this service requires PennKey authentication, so using it to chat and exchange data with other Penn users provides assurance of the identity of the person at the other end of the channel. For more information on Penn’s Jabber service and IM client software for use with it, visit www.upenn.edu/computing/im/.


To receive weekly OneStepAhead  tips via email, send email to listserv@lists.upenn.edu with the following text in the body of the message:  sub one-step-ahead <your name>.

For additional tips, see the One Step Ahead link on the Information Security website: www.upenn.edu/computing/security/.

Almanac - February 17, 2009, Volume 55, No. 22