Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-31 Thread cyphrpunk
On 10/25/05, Travis H. [EMAIL PROTECTED] wrote: More on topic, I recently heard about a scam involving differential reversibility between two remote payment systems. The fraudster sends you an email asking you to make a Western Union payment to a third party, and deposits the requested amount

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-31 Thread cyphrpunk
One other point with regard to Daniel Nagy's paper at http://www.epointsystem.org/~nagydani/ICETE2005.pdf A good way to organize papers like this is to first present the desired properties of systems like yours (and optionally show that other systems fail to meet one or more of these properties);

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-31 Thread cyphrpunk
On 10/28/05, Daniel A. Nagy [EMAIL PROTECTED] wrote: Irreversibility of transactions hinges on two features of the proposed systetm: the fundamentally irreversible nature of publishing information in the public records and the fact that in order to invalidate a secret, one needs to know it;

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-26 Thread Travis H.
If you have to be that confident in your computer security to use the payment system, it's not going to have many clients. Maybe the trusted computing platform (palladium) may have something to offer after all, namely enabling naive users to use services that require confidence in their own

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-25 Thread cyphrpunk
On 10/22/05, Ian G [EMAIL PROTECTED] wrote: R. Hirschfeld wrote: This is not strictly correct. The payer can reveal the blinding factor, making the payment traceable. I believe Chaum deliberately chose for one-way untraceability (untraceable by the payee but not by the payer) in order

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-25 Thread cyphrpunk
On 10/24/05, Steve Schear [EMAIL PROTECTED] wrote: I don't think E-gold ever held out its system as non-reversible with proper court order. All reverses I am aware happened either due to some technical problem with their system or an order from a court of competence in the matter at hand.

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-25 Thread cyphrpunk
On 10/24/05, John Kelsey [EMAIL PROTECTED] wrote: More to the point, an irreversible payment system raises big practical problems in a world full of very hard-to-secure PCs running the relevant software. One exploitable software bug, properly used, can steal an enormous amount of money in an

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-25 Thread John Kelsey
From: cyphrpunk [EMAIL PROTECTED] Sent: Oct 24, 2005 5:58 PM To: John Kelsey [EMAIL PROTECTED] Subject: Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems ... Digital wallets will require real security in user PCs. Still I don't see why we don't already have

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-22 Thread Ian G
R. Hirschfeld wrote: Date: Thu, 20 Oct 2005 11:31:39 -0700 From: cyphrpunk [EMAIL PROTECTED] 2. Cash payments are final. After the fact, the paying party has no means to reverse the payment. We call this property of cash transactions _irreversibility_. Certainly Chaum ecash has this

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-21 Thread cyphrpunk
As far as the issue of receipts in Chaumian ecash, there have been a couple of approaches discussed. The simplest goes like this. If Alice will pay Bob, Bob supplies Alice with a blinded proto-coin, along with a signed statement, I will perform service X if Alice supplies me with a mint signature

Re: [fc-discuss] Financial Cryptography Update: On Digital Cash-like Payment Systems

2005-10-20 Thread David Alexander Molnar
On Thu, 20 Oct 2005, cyphrpunk wrote: system without excessive complications. Only the fifth point, the ability for outsiders to monitor the amount of cash in circulation, is not satisfied. But even then, the ecash mint software, and procedures and controls followed by the issuer, could be