RPOW - Reusable Proofs of Work

mitd writes "Hal Finney is inviting folks to test drive his new hashcash-based server rpow.net. " The RPOW system provides for proof of work (POW) tokens to be reused. A POW token is something that takes a relatively long time to compute but which can be checked quickly." Hal's security model paper is well worth the read and his proof of concept code is available for download. "

Comments

Isn't it obvious?

[BubbaThePirate]

A POW token is something that takes a relatively long time to compute but which can be slashdotted quickly.

But seriously, the server went down after two replies, but not before I managed to get this:

[Read this instead adding a load to a battered server]

"Overview

The RPOW server is designed to provide security and reliability through an unprecedented degree of visibility and transparency in its operations. For the first time it will be possible for any user of the system, anywhere in the world, to know what code is running on the server and to inspect that code for loopholes or back doors. I have done my best to make this system secure even against my efforts as the owner, operator and designer of the system to compromise its operations. I welcome public scrutiny of the code and of the design.

The RPOW system represents a new kind of security model, and is therefore unusually challenging to present and to review. RPOW combines an exceptional degree of physical security with an unprecedented level of transparency and visibility into the workings of the RPOW server. This combination implements the design goal of RPOW as a "Transparent Server", a system whose security properties can be analyzed and evaluated from any system on the internet.

In operation, the RPOW system consists of three parts: the server, the host process, and the client library with its associated demo driver. We will consider each part in turn. "

and this

"RPOW FAQs

Questions

1. What is the RPOW system?
2. How is RPOW pronounced?
3. How do I know the RPOW system is secure?
4. What is the difference between RPOW and Hashcash?
5. What is the difference between RPOW and Ecash?
6. What are some possible applications of the RPOW system?
7. How fast is the server?
8. If RPOW becomes popular, how could one server handle all the users?
9. Won't Moore's Law mean that tokens lose their value over time?
10. Why can't users pass RPOW tokens to each other without using a server?
11. Won't the RPOW server run out of disk space if it keeps track of all tokens it has ever seen?
12. Are you going to make changes to the RPOW system?
13. Why did you choose the IBM4758 Secure Cryptographic Coprocessor as the platform for the RPOW server?
14. Wasn't the IBM 4758 security broken a few years ago?

Answers

1. The RPOW system has three parts: client, host, and server. The client is a software library (plus a simple command-line driver for demonstration purposes) to allow generation and exchange of RPOW tokens. The host software runs on the PC which has the IBM 4758 cryptographic coprocessor card plugged into it. It acts as an intermediary, listening for connections from the net and passing data between client and server. It also assists the server with certain operations. The server runs on the IBM 4758 card and performs the secure cryptographic operations which implement the RPOW system.

2. RPOW is pronounced are-pow.

3. The security of the RPOW system ultimately depends on its design and its implementation. For the design, see the theory and security pages. For the implementation, see the source code available from the download page. The unique properties of the RPOW system design allow you to remotely verify that the program generated from the source code you download here is what is actually running on the RPOW server. If the design and implementation are sound, and that program is what is running on the server, you have a foundation for trust in the security of the system.

4. RPOW uses hashcash for its proof of work (POW) tokens. Hashcash tokens are evidence that a certain substantial amount of computer effort was expended to create them. RPOW allows hashcash tokens to be exchanged for RPOW tokens of an equivalent value, which can then be further exchanged for new RPOW tokens. The effect is similar to being able to pass

Re:Umm

[nova20]

Can someone explain the concept behind this in a little uhh easier terms.

Here's how I understand it:

Imagine you have to do a research paper. Though it takes a long time to write this research paper, what you turn in to your professor is (relatively) quickly checked. The paper itself is like a POW token -- It proves that you did the work without you having to redo the work while the teacher is watching.

-nova20