I previously had been using TrueCrypt, but recently re-installed Ubuntu and used 12.10's full disk encryption option (re-installed for other reasons). I never got any choice in how it did that. I don't know what cipher is used or the key size, or anything besides the passphrase really. Where can I find details about this sda5_crypt?
Edit: Seeing this mistake is humorous, but for those curious, sda5 refers to the hard drive and partition, not the encryption system.