The Authority Base site is an database blogging site run by David Yahalom and as he seems to be blogging about Oracle as well as SQL Server, MySQL, DB2 and LUW I have added his feed to my Oracle Blogs Aggregator.
He has two posts around Oracle security each with some presentation slides. The first is in a post titled Oracle Virtual Directory and it includes a presentation titled Oracle Virtual Directory - From theory to practice and beyond. The second blog post is called The Secure Oracle database - howto and this also includes a presentation titled The twenty-four/seven database - Oracle Database Security.
Whilst this presentation doesn't cover the usual ground that i would (i.e. auditing, internals,forensics,hacking.....) it covers the Oracle products intended to secure the database at a high level and does a good job of putting them all into the right perspective.
I have added his blog to my aggregator so we can keep an eye on new posts more easily.