Brainwallets are secure, but need to be more than just words.
"foo bar baz" is a terribly passphrase, for instance. "foo bar baz lyndsy@lyndsysimon.com" is a much better passphrase - it's trivial to use a bit of personal information as a salt, thereby providing substantial protection against non-targeted attacks.
"foo bar baz" is a terribly passphrase, for instance. "foo bar baz lyndsy@lyndsysimon.com" is a much better passphrase - it's trivial to use a bit of personal information as a salt, thereby providing substantial protection against non-targeted attacks.