[Yaffs] Secure Delete of Files on YAFFS2

I have a question about what YAFFS2 supports for providing a mechanism
to securely delete a file so that it cannot be recovered once deleted.

We are looking for a file system that supports the concept of secure
delete, either by performing a block erase that encompasses all
outstanding pages, or by utilizing Cryptographic Encryption on a
per-file basis.

Our main requirement is to support the ability to perform a secure
delete. We do not require the data on the drive to be unreadable
until we go to delete the file. If we are using Cryptographic
Encryption we would need the encryption key that is used to be unique
per file as we would only want to have to delete a single file to
cause the contents to become unreadable.

I took a look at the yaffs.net site and didn't see anything that
seemed to specifically outline that it supports Cryptographic
Encryption itself or what level of encryption that it is using. I
have seen a few research papers on people that have made the
modifications themselves.

Am I missing something, or is it accurate that YAFFS2 does not support
any secure delete functionality or a Cryptographic Encryption feature
that could be used for the same purpose.

Thanks,
--
Bradley Remedios
bremedios@gmail.com