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Show HN: Kong – Physical Cryptocurrency

kong.cash

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Re: Show HN: Kong – Physical Cryptocurrency

#251

Post by suyash »

ccamrobertson wrote: post #2

Hi folks, I’m one of the contributors at Kong — https://kong.cash/ . Kong is a physical cryptocurrency that looks, feels and works like traditional cash. You can think of it as an ultra-secure, time locked cryptocurrency wallet with a fixed face value — no one can access the token except for the holder of the note after a period of several years. It consists of a secure element and NFC chips mounted on a flexible PCB…

What's the value of 1 Kong in USD, showing that would be helpful on your website front page.

Re: Show HN: Kong – Physical Cryptocurrency

#252

Post by ccamrobertson »

jakelazaroff wrote: post #242
ccamrobertson wrote: post #234

Earlier quoted context omitted.

Today, Kong's printing is centralized to the Kong project (similar to a premine) because we cannot guarantee that someone else will use a secure element which conforms to section 2 of the paper (which would preclude the creation of duplicates). If anyone else wants to print Kong, and we can verify they source a secure element conforming to section 2 of the paper, then we'll share "printing rights" with them. The Kong…

Is this not strictly worse than cash, then? It’s still a centralized physical currency, but instead of a government with checks and balances that is ostensibly accountable to its citizens, Kong is controlled by an opaque organization accountable to nobody. After reading the paper, I’m still not exactly sure how the lockdrop works. Could you elaborate on it? As for verifying transactions offline, I’m skeptical of how…

We can only print Kong; we cannot remove it from circulation. We're limited in the total amount of Kong we can print.

We likely will need to have another document detailing how the lock drop works. The short version is that you lock up Ethereum in a smart contract for between 30 and 365 days; when you prove that fact to a given Kong lock drop contract instance you receive Kong token (at the end of the period).

> If you decentralize printing (or a lot of counterfeit/duplicate Kong gets introduced into the market some other way) then offline verification seems insufficient. What’s to stop me from printing and spending two copies of a note if I know the other parties won’t certify the transaction online until much later?

Here's how I see offline verification working:

(1) I sync up directly with an Ethereum node and cache all the Kong note smart contracts (ideally my own would be the most trustworthy). Most importantly this contains the public key for each Kong note known at the time and the token associated with that note (2) I accept any notes that I can electronically verify from that cache. That's done by challenging the note to sign a message and verifying the response. (3) I don't accept any notes not in my cache. The downside is that I can't accept very new notes, but we suspect that if we continue to produce Kong that we'll do so in large batches infrequently.

Re: Show HN: Kong – Physical Cryptocurrency

#253

Post by shpx »

ccamrobertson wrote: post #2

Hi folks, I’m one of the contributors at Kong — https://kong.cash/ . Kong is a physical cryptocurrency that looks, feels and works like traditional cash. You can think of it as an ultra-secure, time locked cryptocurrency wallet with a fixed face value — no one can access the token except for the holder of the note after a period of several years. It consists of a secure element and NFC chips mounted on a flexible PCB…

Which "secure computing element" are you using?

Re: Show HN: Kong – Physical Cryptocurrency

#255

Post by darawk »

jakelazaroff wrote: post #250
darawk wrote: post #244

Earlier quoted context omitted.

> That flaw is mostly a non-issue with cash because printing it is difficult. That depends entirely on how good your fake is. And it is most certainly not 'mostly a non-issue'. Counterfeiting happens all the time. > Who prints Kong? I imagine prevalence of counterfeiting is more or less directly proportional to the ease of printing. Nobody. Kong is printed algorithmically, like any other cryptocurrency.

> And it is most certainly not 'mostly a non-issue'. Counterfeiting happens all the time. How often have you had any real-life issues with counterfeit money? How often has anyone you know? How often have you even heard of it happening, relative to how often you see and hear of cash being used? A sibling comment provided a source that said that only 1% of 1% of cash is counterfeit. > Nobody. Kong is printed algorithmi…

> How often have you had any real-life issues with counterfeit money? How often has anyone you know? How often have you even heard of it happening, relative to how often you see and hear of cash being used? A sibling comment provided a source that said that only 1% of 1% of cash is counterfeit.

Stores have issues with it all the time. That's why they don't often take large bills. I and my personal acquaintances don't accept a lot of cash in exchange for goods and services.

You think 1% of cash being counterfeit is not a problem? That sounds like a huge problem to me.

> What? Notes and coins are a human-made physical items. They’re manufactured by someone.

Sure, the physical objects are made by someone. But the digital tokens to which they refer are produced algorithmically, and the digital tokens are the source of truth here.

Re: Show HN: Kong – Physical Cryptocurrency

#256

Post by paulgerhardt »

suyash wrote: post #251
ccamrobertson wrote: post #2

Hi folks, I’m one of the contributors at Kong — https://kong.cash/ . Kong is a physical cryptocurrency that looks, feels and works like traditional cash. You can think of it as an ultra-secure, time locked cryptocurrency wallet with a fixed face value — no one can access the token except for the holder of the note after a period of several years. It consists of a secure element and NFC chips mounted on a flexible PCB…

What's the value of 1 Kong in USD, showing that would be helpful on your website front page.

Kong is very new. Only a few thousand are out there. Frustratingly, or perhaps amusingly, it doesn't yet have an agreed upon value. I don't think it's appropriate for us to set one.

Re: Show HN: Kong – Physical Cryptocurrency

#257

Post by jakelazaroff »

ccamrobertson wrote: post #252
jakelazaroff wrote: post #242

Earlier quoted context omitted.

Is this not strictly worse than cash, then? It’s still a centralized physical currency, but instead of a government with checks and balances that is ostensibly accountable to its citizens, Kong is controlled by an opaque organization accountable to nobody. After reading the paper, I’m still not exactly sure how the lockdrop works. Could you elaborate on it? As for verifying transactions offline, I’m skeptical of how…

We can only print Kong; we cannot remove it from circulation. We're limited in the total amount of Kong we can print. We likely will need to have another document detailing how the lock drop works. The short version is that you lock up Ethereum in a smart contract for between 30 and 365 days; when you prove that fact to a given Kong lock drop contract instance you receive Kong token (at the end of the period). > If y…

> We can only print Kong; we cannot remove it from circulation.

This isn't strictly true; you can buy notes from people.

> We likely will need to have another document detailing how the lock drop works. The short version is that you lock up Ethereum in a smart contract for between 30 and 365 days; when you prove that fact to a given Kong lock drop contract instance you receive Kong token (at the end of the period).

It sounds like the basic idea is that you "preorder" Kong with Ethereum, and then you visit a physical location (the "contract instance") to receive your cash ("Kong token"). If my understanding is correct, then this isn't outside of your control at all — you (or the "contract instance") can simply refuse to issue the cash.

Re: verification, here's my issue:

> Most importantly this contains the public key for each Kong note known at the time and the token associated with that note

What if someone counterfeits Kong not by wholesale faking currency, but by duplicating valid notes in circulation? The public key would be the same, so they would both pass offline verification.

Re: Show HN: Kong – Physical Cryptocurrency

#258

Post by luxuryballs »

jakelazaroff wrote: post #242
ccamrobertson wrote: post #234

Earlier quoted context omitted.

Today, Kong's printing is centralized to the Kong project (similar to a premine) because we cannot guarantee that someone else will use a secure element which conforms to section 2 of the paper (which would preclude the creation of duplicates). If anyone else wants to print Kong, and we can verify they source a secure element conforming to section 2 of the paper, then we'll share "printing rights" with them. The Kong…

Is this not strictly worse than cash, then? It’s still a centralized physical currency, but instead of a government with checks and balances that is ostensibly accountable to its citizens, Kong is controlled by an opaque organization accountable to nobody. After reading the paper, I’m still not exactly sure how the lockdrop works. Could you elaborate on it? As for verifying transactions offline, I’m skeptical of how…

> but instead of a government with checks and balances that is ostensibly accountable to its citizens

what government is this and can I vote my face onto their currency?

Re: Show HN: Kong – Physical Cryptocurrency

#259

Post by ccamrobertson »

jakelazaroff wrote: post #257
ccamrobertson wrote: post #252

Earlier quoted context omitted.

We can only print Kong; we cannot remove it from circulation. We're limited in the total amount of Kong we can print. We likely will need to have another document detailing how the lock drop works. The short version is that you lock up Ethereum in a smart contract for between 30 and 365 days; when you prove that fact to a given Kong lock drop contract instance you receive Kong token (at the end of the period). > If y…

> We can only print Kong; we cannot remove it from circulation. This isn't strictly true; you can buy notes from people. > We likely will need to have another document detailing how the lock drop works. The short version is that you lock up Ethereum in a smart contract for between 30 and 365 days; when you prove that fact to a given Kong lock drop contract instance you receive Kong token (at the end of the period). I…

> This isn't strictly true; you can buy notes from people.

Haha, sure.

> It sounds like the basic idea is that you "preorder" Kong with Ethereum, and then you visit a physical location (the "contract instance") to receive your cash ("Kong token"). If my understanding is correct, then this isn't outside of your control at all — you (or the "contract instance") can simply refuse to issue the cash.

Nope, it's in a smart contract that can be deployed into perpetuity.

> What if someone counterfeits Kong not by wholesale faking currency, but by duplicating valid notes in circulation? The public key would be the same, so they would both pass offline verification.

Section 2 in the paper explains how difficult this would be do. You need to duplicate the private key from a secure chip designed not to reveal the private key.

Re: Show HN: Kong – Physical Cryptocurrency

#260

Post by jakelazaroff »

darawk wrote: post #255
jakelazaroff wrote: post #250

Earlier quoted context omitted.

> And it is most certainly not 'mostly a non-issue'. Counterfeiting happens all the time. How often have you had any real-life issues with counterfeit money? How often has anyone you know? How often have you even heard of it happening, relative to how often you see and hear of cash being used? A sibling comment provided a source that said that only 1% of 1% of cash is counterfeit. > Nobody. Kong is printed algorithmi…

> How often have you had any real-life issues with counterfeit money? How often has anyone you know? How often have you even heard of it happening, relative to how often you see and hear of cash being used? A sibling comment provided a source that said that only 1% of 1% of cash is counterfeit. Stores have issues with it all the time. That's why they don't often take large bills. I and my personal acquaintances don't…

1% of 1% (so .01%). Is refusing large bills an effective countermeasure? If so, then yeah — not really an issue. Our economy somehow grinds along just fine.

> Sure, the physical objects are made by someone. But the digital tokens to which they refer are produced algorithmically, and the digital tokens are the source of truth here.

In what sense? The whole idea here is that I can exchange a physical note to transact with someone.

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