Unsanity.org: Love Tropicana: The Fix for securityd Eatings Gobs of Ram When Updating Keychain Entries

For the past few months, I've suffered the most vexing and stubborn OS X problem I've ever had to confront. Detailed in this Apple.com forum thread, the short version is that something with my Keychain went haywire somewhere, and any time I had to reauthorize an application's access to the Keychain, the securityd process would spin off into the stratosphere, grabbing an enormous amount of RAM, virtually freezing my Mac, and never letting go until I did a full-on, old-school restart (CONTROL-COMMAND-POWER). This was frustrating.

In addition to leaving me without NetNewsWire, OmniWeb, and several other of my Top 20 apps, I lost reliable access to Transmit, which for me is like losing a fingertip or something.

I'll save you the ridiculous amount of rubber chicken waving (and Keychain item decimation) that ensued, and will just cut to the solution, which was provided by Unsanity's Rosyna.

In order to fix this problem if you are having it, just open the Terminal (/Applications/Utilities/Terminal) and type:

sudo mv /var/db/CodeEquivalenceDatabase /var/db/CodeEquivalenceDatabase.old

or

open /var/db (and then manually move CodeEquivalenceDatabase to the trash, if you can).

I don't know precisely how or why this works (short answer: "file corruption bad"), and I cannot assure you that it will not, in your own usage, cause Big Problems™. But it worked for me, I have my apps back, and now I'm the happiest boy in the world. May Google bring others to the solution as well.

Many thanks to Rosyna, who is so going to get a present for this.