Passwords

The latest password issue at LinkedIn has got me looking through all my passwords to make sure I'm not repeating anything, especially anything that I used at LinkedIn. I tend to use a few base words, and add numbers, or phrases and numbers to them, but, to be honest, it is getting difficult to keep track. I actually have a document where I keep my password list, although in the document, I use hints to tell myself which base word I am working from. I'm sure this is not secure enough. People have been talking about password management apps, but I don't even know what that means. I guess it's time to do some reading...

Meanwhile, I'll be putting the document in some semblance of order over the next few days. What do you guys use to keep track of all your passwords?