AES 256bit File encrypt in sandbox. Encrypt mode is CBC. Key is derive by PBKDF2. If your chorme(chromium) support PNaCL, you should use PNaCL ToraTora. This software is inferior to PNaCL ToraTroa. It is convenient to transfer in internet. Because you can recommend this software for sandbox. JSToraTora can't access local disk on your PC. So You can be used safely.
Google Chrome 47.Vivaldi Ver1.1
Tested OS : FreeBSD 10.0 / PC-BSD 10.0
Original ToraTora can encrypt by smartcard. And you can encrypt by smartcard without smartcard. Because you can use USB flash drives as smartcard. This is enabled by myuToken.
Install from Chrome Web Store
How to use
Please see here.
asmCrypto : MIT License
Even if damaged by the use of JSToraTora, it does not take any responsibility.