RSE - The Reliable Security Environment

The Reliable Security Environment

- A Pretty Good Solution For Really Bad Networks -

January 2000

RSE IS NOW AVAILABLE.
Please feel free to mail your comments to me!

The Problem

Unfortunately everyone who is willing to use PGP in a networking environment is confronted with a problem, I have described in detail, the risk of disclosure of your secret-key.

All kinds of possible attacks on the security of your secret key are lurking around in a networking environment beginning with vulnerabilities of your operating system allowing snooping attacks to undesired side-effects using network software like browsers and other TCP/IP-based information systems.

Even if you are careful when using your passphrase, you don't know in which condition the computer system you have just logged in is at the moment, and you don't know, whether your keyboard input isn't going anywhere you don't know. You simply have no access to a computer system which is reliably secure to use your passphrase and to enjoy its secrecy for your lifetime.

If you don't have this problem, you are lucky, and you will never need RSE, because you have already a computer system you can rely on.

SECT - The Secure Terminal

But if your computer system is not reliable for using PGP and you have access to another system that offers you reliable security somewhere out on the net you can turn your local computer into a secure terminal (SECT) by booting a single disk, I call SECT-disk.

Once you have booted SECT your local PC is turned into a LINUX system which provides reliable security so that you can establish a cryptographically secured connection (Secure Shell) to your reliable system somewhere out on the net, and you can safely enter your passphrase locally, even if there is something next to Sodom and Gomorrah happening on the other systems connected to your completely unreliable local network.

RSE - The Reliable Security Environment

But if you don't have access to some reliable system on the net you can turn your local PC into a safe system, safe to enter secret passwords for PGP, using another disk which creates the Reliable Security Environment (RSE) on your local system. The RSE-disk holds your PGP-secret-keys doubly encrypted and provides all functionality to read and compose email and to sign documents without a risk of disclosure of your secret-key while your computer is still connected to a totally unreliable network.

What is Reliable Security ?

Everyone who promises total security should be treated with great suspicion. But RSE does not make this promise, and I'd like to emphasize, that RSE is designed to provide as much reliability as possible, so that you can be sure, your system is working in a reliable way, using carefully selected software to avoid risks that can be avoided.
Total security means nothing will go wrong. Nobody with some experience in complex information technology will regard this being possible during this millennium. But reliable security means that something important - like the use of PGP - is being performed in a certain way you can rely on every time you are booting your SECT and RSE-disk.

So what can you expect from the "Reliable Security Environment" ?

You will be using LINUX, which is reduced to a minimum of files on the SECT-disk. The source code of LINUX is publicly available but even if the ordinary user would not scrutinize the complete source code, experts can take a close look on security relevant parts of LINUX and can warn the community. (Tranparency)
The whole system will be running in RAM, the main memory of the computer, so that every secret will ultimately be forgotten when the power is turned off. No part of the filesystem will be located on a permanent storage, so that you can switch your computer off at any time although you are running UNIX. (Protection of filesystem)
All traffic to the local network over the ethernet will be blocked, except the indispensable SSH-trafic (SECT) and POP/SMTP-traffic (RSE). Some people call this a firewall. The local system will be running none (SECT) or very few server-processes (RSE) and will be inaccessable as much as possible. (Minimal connectivity)
Your ssh-secret-key will be stored on the SECT-disk and there is no more encryption than SSH itself provides, which is strong encryption as well. All your pgp-keys will be stored on the RSE-disk using pgp twice so that your secretkey-ring will not be accessable if you forget your RSE-disk in the drive, which will surely happen. So everything depends on you selecting two secure passphrases, one to protect your secretkey-ring and one for your encrypted backup to the RSE-disk. (Strong encryption)
RSE provides a mail client (pine) and a software (securemail) which integrates pgp into your mail client in a transparent way, so that you don't have to deal with pgp on the command line, but you can see pgp being invoked by open-source filter software. (PGP-integration)
And last but not least RSE provides PGP-2.6.3i which has been compiled using checked source code. (Trusted software)

Intellectual Property

Most of the content of both disks is not my intellectual property!

The Reliable Security Environment uses :

For a few scripts, mostly in /root and /RSE/bin and /RSE/securemail, all of them I have signed with my PGP-key I would like to claim intellectual property, as well as for the idea of designing RSE.