Renzhi Safe
Introduction
In a word, Renzhi Safe is an encrypted virtual safe, or an encrypted virtual disk, or an encrypted virtual volume, or an encrypted virtual data storage device.
For a longer description, Renzhi Safe is an Android application for establishing and maintaining an encrypt-on-the-fly safe (or volume, or data storage device). Data are automatically encrypted before they are saved, and decrypted after they are read, without any user intervention. No data stored in an encrypted safe can be read without first opening the safe with the correct password. The safe contains an entire file system, which is encrypted (e.g., file names, folder names, contents of files, free space, any other information).
Files can be copied to and from an opened safe just like they are copied to and from any normal folder. You can also perform drag-and-drop operations. As you read or copy a file from the safe, it is automatically decrypted. Similarly, as you move or copy a file to a safe, it is automatically encrypted on-the-fly.
Suppose you keep a secret photo inside a safe. After the safe is opened with the correct password, you can see the photo file, and view it with any photo viewer application that you have installed on your Android device. Once you are done viewing it, you can close the safe (i.e. lock it).
A built-in file browser allows you to work with the contents of your safes, your folders and files easily.
Main Features
- Creates a virtual encrypted safe within a file and open it as a folder.
- Encrypts an entire safe, not just a specific data file.
- Encryption is automatic, real-time (on-the-fly) and transparent.
- Uses AES algorithm, with 256-bit encryption keys.
- Creates as many safes as your storage allows.
- Creates as large a safe as your storage allows.
- Opens multiple safes at the same time.
- Contains a whole file system.
- Encrypts whole file system, including folders and sub-folders, data file, metadata, etc.
- Encrypts different safes with different passwords.
- Encrypts and decrypts really fast.
- Opens and operates just like a normal folder.
- Works with any other Android applications transparently.
- Work with multiple SD cards
- Keeps virtual safe container files on different SD cards.
- Backup and restore encrypted safes.
- Close all safes in one command.
- Option to check if a safe is busy, i.e. any other app is currently using the contents of the safe.
- Option to force close a safe even if a file in the safe is currently busy.
- Built-in file browser.
- Option to shred file before deleting.
- Option to display thumbnails or not.
- Start up in Safe Management mode or in File Browser mode.
You can read the Release Notes here, and the User’s Guide here, and the FAQ here.
NOTES:
Your Android device must:
- Be rooted
- Have SuperUser installed
- Some stock kernels do NOT work
Roadmap
Planned features for future releases:
- Add multi-select to file browser.
- Add functionalities to create archive and unzip archive (depends on multi-select feature)
- Add search to file browser.
- A shortcut to close all safes in an emergency, without having to bring up the Renzhi Safe app, e.g. shake your Android device in a specific patterns to force close all safes.
- An option to securely wipe the contents of a safe container during delete, not just deleting the files, so that crackers can’t even try to crack it.
- Link the security of a safe to the security Android. When the user unlocks Android, the safe is automatically opened, when the user locks Android, the safe is close (Mohammad Ghasem Nejati Rad suggested the idea).
- Master password for safes management and operation, e.g. edit, delete, etc.
- An option to check Android device compatibility. Some vendors are known to exclude some important modules in their kernel, this makes Renzhi Safe unusable on those devices. We’d like to be able to verify usability first, instead of waiting for things to explode when users start using it.
- Advanced/Pro mode, allowing users to select encryption algorithm and key size during safe creation.
- Integrate with PGP/GPG, allowing users to specify an encryption key, instead of just using a password.
- Resize an existing safe to make it larger.
- Remote safe container. Have the safe container file hosted on a remote safe, e.g. SSH server, SFTP server, DropBox, etc, and open it locally on the Android device as if the safe is on the device.
- Generate thumbnail for all file types (pdf, office, open office, video, etc)
- Show more file properties, depending on file types, e.g. Office document.
- Add option to set time-out time for open safe, and automatically close the safe after a pre-set time.
If you have other ideas and requests, you are welcome to contact me. If your good idea is incorporated as a feature, you will be “compensated” with a free copy of Renzhi Safe 
How does it compare to TrueCrypt?
From the user’s point of view, it works similarly, you create an encrypted virtual disk, you mount it, you use it as any normal disk, once you are done, you umount it. Except that Truecrypt has a hidden volume, a nice feature to have. Renzhi Safe is based on Linux disk encryption, and not Truecrypt.
In the future, there should be an option to mount a safe on a computer under windows, linux and/or os x.
Since this is based on Linux encrypted disk, by default, it is mountable on Linux. I already have my safes shared betwen Android and Linux. You can just export the volume (to be in the next release) and mount it on Linux. On Windows and other OS, that would be another issue. The intention is to create a portable encrypted format in the future.
>The intention is to create a portable encrypted format in the future.
It would be great if this format was TrueCrypt format or FreeOTFE format
The first thing I looked at was Truecrypt when I needed an encrypted disk for my personal use on Android. However, it seems that they have no plan to port it to Android, which is quite understandable due to the following reasons:
- Truecrypt requires to have FUSE compiled in the kernel, or loaded as module
- Most manufacturers have chosen to exclude a lot of kernel modules from their ROM, and FUSE is probably not even on their radar.
Therefore, it would be quite a task to support Truecrypt. And I think the license for Truecrypt format is inseparable from the license of their source code, so there’s no other third-party support for that format. It’s nice though.
FreeOTFE is Windows-based only, porting it to Android (and Linux) would have the same issue as Truecrypt. But yeah, I was thinking of supporting FreeOTFE too, as the format seems not that hard to support.
Excellent app, very nice UI, and very easy to use, and the only one on the market so far, for managing encrypted virtual disks, especially with UI that even non-tech people can use.
However, I think you would get a lot of low ratings on Android Market, because most people do not understand
As you said it, a lot of hardware vendors had chosen to exclude some of the very important kernel modules, and it made Renzhi Safe unusable. And I think that’s why other people had decided not to develop anything similar, because it would be a support headache. But it’s cool you did it, with excellent UI too.
I saw you had published a trial version. I would recommend against it, for this kind of application, a free trial version is not worth it. People who do not understand would install any app, as long as it is free, and give a low rating if it does not work out on their device. Although there’s no rating yet (last time I checked), but I bet $100 that you will get very low ratings for that
I’d hate to see low ratings on good apps, specially from people who don’t understand. I think that those people should not rate it.
Excellent app! Just installed it a couple of days ago, works great! Can’t wait to see the new features listed on the roadmap.
I wouldn’t bet against James
As predicted by James, the low ratings are already coming. That’s not fair.
>FreeOTFE is Windows-based only, porting it to Android (and Linux) would have the same issue as Truecrypt.
As an example you can look at LUKS Manager that declares FreeOTFE FAT volume support. Unfortunately, this feature doesn’t work on my device yet (tegra 2 tab). I can’t open FreeOTFE FAT volume in LUKS Manager and vice versa.
Thanks all for your comments and suggestions. This app wasn’t intended for everyone, so as long as someone finds it useful, it’s cool by me.
@bogser,
I haven’t had a chance to play with FreeOTFE, so I’m not sure. I’ll take a deeper look later.
I’m using LUKS manager now, but the interface of Renzhi Safe looks really cool. Good work. I’ll try it someday, probably when a next version comes out, with the mentioned features
Hi there
Great app. I’ve been looking for an Android alternative to FreeOTFE for a long time and now it’s finally here
My first impression is very good and it will definately get good ratings from me if my tests runs ok.
Cheers!
Hi Søren,
Thanks. If you like it, please help with rating and reviewing
Please support FreeOTFE FAT volume. It would be a killer app. I have a few FreeOTFE volumes that I’d like to import onto my Android.
Cheers
Just downloaded the free version and will test it soon. I am also a frequent user of freeotfe for windows mobile pocket pc and windowsxp. For linux, i use truecrypt because i can access my encrypted volume across different operating system platform. I will definitely rate this app very high if it can support volumes created by freeotfe! Thanks for the application and look forward to future development.
Can’t wait to see the next version, with the planned features. I vote for the following:
1) Easy backup and restore
2) Shortcut to close all safes in emergency. I think shake the device to close all would be cool.
3) Securely wipe the safe container during delete.
4) Integration with GPG.
Thnx
[...] intention of that permission was for a remote encrypted safe container, which is described in my roadmap. This is to have a safe container hosted on a remote server, e.g. ssh server, ftp server, dropbox, [...]
This works like freeotfe4pda did, thanks so much. Any chance you can recompile to run on a PC like freeotfe did? That way the same volume could be managed on either platform. Great job.
It may work like freeOTFE, but it’s based on Linux disk encryption. I think it would take some work to port it to Windows, but yeah, it would be cool.
But as the author said, you can mount the volume on Linux.
Really neat. Works great!
Thanks
Just upgraded to the latest version v2.1.1, works great, even on my Transformer. Excellent work.
Cheers
Installed free version from the market, works fine on 2.3.6 custom rom(but not on 2.3.3). Not a big deal, but could create a safe only 20 MB, not 50. 5 stars and one request – after the safe unmounting its folder still stays on the drive. Can you please make an improvement in the next free version to automaticaly remove its access directory. Or may be it is done in the full vesion, would like to know.
Thank you.
I think it would be better to keep the access directory when the safe is not open. It is more intuitive this way.
Excellent app. Thanks
I am in china, how to buy it?