Secure Data Application for the eBookMan

1.0 File List

Below is a list of included files and what they are for:

1.1 Secure Data Introduction

The Secure Data application provides a way to keep personal data on your eBookMan.  The data is encrypted and saved into one or more "sdat" files.   The key used for the encryption operations is provided by you.

You may use different keys to store different sets of private data into one or more sdat files.  The data may be categorized in a hierarchically format and data items can either be generic name-description records, or an entire embedded files (which are decrypted back to files when open).

Secure Data will automatically "wipe" its internal memory on a variety of events.
 

1.1 Initialization

The first time you run Secure Data there is no data.  By default Secure Data does not allow any access until at one of the valid passwords is supplied.  So on first invocation you are requested for a "new catagory" password.  This will be the first valid password you can then use to Login into Secure Data.
 

2.0 Multiple sdat files

Secure Data will only create "Secure Data.sdat" as an eBookMan ram file.   However, you can utilize the sdcode program to create other sdat files, or you can copy the current "Secure Data.sdat" to another name.   Additional sdat files may be located in ram or on the MMC.   Only files that are in ram will allow edits.  

While it may seem silly to make copies of your Secure Data.sdat file it useful if you want to move largely static data to an MMC file.  E.g., after you've create your personal information, which is not going to change much, you can move it to an MMC sdat file so it doesn't need to use your valuable eBookMan RAM.

Note that if you use the eBookMan Desktop Manager to copy or move the Secure Data.sdat file you will find it hard to change the name of the file.  To change the file name you need to download it to your PC, use an "unseb" tool, then rename the resulting file.   You can then upload it under the new name to either the RAM or MMC.

Note that Secure Data does require at least 1 read-write ram file (named Secure Data.sdat) to be present.  In addition to using the file to store personal data records, Secure Data also stores various program state into this "main" sdat file.

2.1 import.sdat text file

A quick way to load a bunch of data into Secure Data is to build your own import.sdat file.  For the format of the file check the example import.sdat file included in the zip archive.  Once you have made your own file, you can import the data to an sdat file one or two ways.

The first is to simply use sdcode.exe and supply import.sdat as the input filename.  sdcode will parse and add the records to the output sdat file.  You can then upload this file to the eBookMan.    This is the easiest way to get your data to the MMC as it saves steps when compared to the second method which uses the eBookMan to import the data.

The second options is to upload import.sdat it to the eBookMan, login with a valid password, and then use the menu option to "import items".   This will cause Secure Data to read your import.sdat file and encrypt its entire contents into Secure Data.sdat.   Be sure to delete import.sdat once you have imported its data.  (Note do not rename import.sdat to any other name or the operation may fail).   At this point you can be done with your importing, but this leaves your data in RAM - which is OK, but you might want it on the MMC instead so its not lost if your eBookMan loses power.   To move the file to the MMC see section 2.0.

2.2 Multiple passwords

Each sdat file can support as many passwords as you like.  If you are using sdcode, simple run it multiple times each with the password you want for that data.   When Secure Data starts, you must supply a password that is valid in at least 1 sdat file on your eBookMan at which point Secure Data will generate a list of the sdat files that contain data for that password. 

You may also create new passwords in the ram file "Secure Data.sdat" on the file with Secure Data.  To do this, you first need to gain access by using any existing password.  Then call up the menu and select "New Cataogry".  You may then create a new password in the "Secure Data.sdat" file.

3.0 sdcode.exe

This program is a command-line windows application.   You can use it on your PC to create sdat files, that you then upload to your eBookMan.   It can package up files and parse import.sdat style files to package up records.  You supply the password/key you want the data to be encrypted with on the command line.   Once you've packed your data into an sdat file, simply upload it to your eBookMan.  To access it you supply the ket that you packaged the data with and Secure Data you will decrypt the data as its accessed.

This is a handy way to encrypt a bunch of files at once.  (As opposed to uploading them to the ebookman and doing it there).

For exact program usage run "sdcode -?".  Here are a couple of examples:

I use the sdcode program for 99% of my data that goes into sdat files.

3.1 Virtual Delete

Since MMC files are "read-only" I added functionality to Secure Data to "virtually delete" entries in sdat database files that reside on the MMC.   Such files are not actually deleted from the sdat file and instead and simply "hidden" by Secure Data.

Note Secure Data stores the virtually deleted information into the main Secure Data.sdat file.
 

3.1 Non-encrypted files

Given the usefulness of the hierarchical store within an sdat file, the virtual delete ability, and the performance degradation of the eBookMan as more files are present I added the ability to put unencrypted files into an sdat. This can only be done when using the sdcode.exe tool by using the '-p' (plaintext) flag.   Files added to an sdat file this way are stored under the supplied key, but are otherwise stored in plaintext in the sdat file.   

The advantage here is that they can be extracted much more quickly then an encrypted file, and you can use the virtual delete function on them.  And as a side effect you reduce the number of files on the eBookMan thus reducing some of the delays that are present.

I use this feature to store numerous books and documents into a small number of sdat files.  I then only extract the one I want to read.  And when I'm done I can virtual delete them from the file list.  Right now I have a 73 gigabyte sdat file on my MMC card with piles of books from blackmask.  They are all stored in a nice directory tree so they are easy to find.  When I need something to read, I just copy one out to eBook ram and read it.  Later I can virtually delete it, etc..
 

3.2 Non-encrypted compressed files

When using the '-p' flag you can also supply the '-c' flag which will perform some slight compression on the file as well.   But note this will significantly slow down the extraction process on the eBookMan.

On prc book files it saves around 10%, but given the performance slow down on the eBook to extract, I'm not using this on any book files which are large.   On text files it compresses better.

Note encrypted files in an sdat are always compressed before encryption. (This is a "convention" in Secure Data and sdcode.exe).