[Nxt] Decentralized App Store

[BCNext]

This thread is dedicated to discussion of Nxt (https://bitcointalk.org/index.php?topic=303898.0) and its features.

Nxt has different features that make decentralized services real.  One of these features -- Messaging -- can be used to sell/buy digital goods represented by plain text.  Particularly to sell applications for computers/phones.

The workflow looks quite simple
1]  A developer sends a message describing a product (it's stored on the blockchain).
2]  A user sends a payment to the developer's account.
3]  The developer sends an encrypted message with a link or a code (stored on the blockchain as well).
4]  The user decrypts the message and uses the code to unlock premium in the application.

Key points
1]  Developer publishes their account on their webpage to prove they are the legitimate owner (or uses Reputation System of Nxt)
2]  All actions are public and can be audited (the encrypted message can be audited if one of the parties reveals the key)
3]  Only transaction fees are charged, 100% profit goes to the developer
4]  Noone can shut the store down nor they can DDoS it

Nxt client will have widgets that scan the blockchain and visualize digital goods.  I'd like to hear how this should look and what features should be implemented in the client software.

[kriwest]

First of all I want to say that I love these innovative ideas you have.

About the design... it's hard to say, but the first thing that comes to mind is that it needs to have a way to easily categorize, as well as search for, the digital goods. Even the Google play store doesn't have a very good categorization ability.. if I want to find a game, I can... if I want to find all roleplaying games... I can't. Which is pretty stupid.

[albitos]

I have one doubt - what about blockchain size? Won't it be a problem long-term? I have a great idea how it could be used in a decentralized subscription model, but there could be a lot of data (probably several gigabytes in the long term). Specifically speaking I would like to store RSS channels that can be updated only by owners which would store links to files.

[BCNext]

1]  Each year the blockchain will be shrunk (automatically)
2]  A cloud version of the client should resolve this issue for users with low-end hardware
3]  Messages won't be included into the blockchain for free, you still have to pay a transaction fee, so you can't misuse this feature

[bybitcoin]

Why not storing messages and all other extra stuffs in an embedded blockchain outside the main one, and make them interacting to each other?
what is the mechanism for controlling the purchase of the goods, if a seller receives cash and do not release the product? Since there is a possibility of publishing fake non-existent products which may scam a lot of people before the network globally get awareness about and react. What is your provision for this?

[BCNext]

Why to split data among different chains?  Keep it simple.

Reputation system will help to fight scammers.  It will not remove them completely but still...

[bybitcoin]

Why to split data among different chains?  Keep it simple.

Reputation system will help to fight scammers.  It will not remove them completely but still...

Because you seem to have a way to resolve the well known blockchain bloating problem (apparently by cutting it annually, though I guessed you may use a merkele tree first). Messaging and other stuff may bring a lot more chain volume that brings the bloat headache the other way.

[BCNext]

Messages will compete against transactions to be included into blocks.  It doesn't matter what bloats the blockchain -- messages or transactions.

We must understand that real world sets some restrictions and we can't bypass them.  The blockchain is a scarce resource we just have to find equilibrium between volume of data and fees.  That is what Economics for.

[sepehr]

This is a revolutionary Idea that I have not read about anywhere else here!
It should be informed to the Coin community about this Idea.

[extee]

you can say what you want about BCNext but he's a genius.

[allwelder]

4]  Noone can shut the store down nor they can DDoS it

just want to know,how to come true this ?

[v39453]

Could we have decentralized buying and selling of files (with any content)?

https://bitcointalk.org/index.php?topic=345619.msg5566784#msg5566784

[5flags]

Outstanding. Looking forward to having a play with this.

Could be used to buy/sell crypto currencies by storing the address and private key and releasing them to a buyer? Or do I misunderstand?

[v39453]

Outstanding. Looking forward to having a play with this.

Could be used to buy/sell crypto currencies by storing the address and private key and releasing them to a buyer? Or do I misunderstand?

I think so, yes. There is a danger that the seller would spend the coins at the same time as he sells them. But I think I read on the other thread that somebody is working for atomic cross-chain transactions, which would solve this issue, but I don't know a lot about that.

[msin]

Outstanding. Looking forward to having a play with this.

Could be used to buy/sell crypto currencies by storing the address and private key and releasing them to a buyer? Or do I misunderstand?

I think so, yes. There is a danger that the seller would spend the coins at the same time as he sells them. But I think I read on the other thread that somebody is working for atomic cross-chain transactions, which would solve this issue, but I don't know a lot about that.

Good to see this discussion continued here, hard to follow in the massive Nxt thread.  I still like the idea of magnet links listed in the client, click and the marketplace GUI is loaded into the client.  There was a BTT member (Fry) that was interested in developing.  Would love to get more brainstorming here, this could be a great thing to have.

[v39453]

My vision could be called NxtPrivateMarket, as opposed to the Nxt asset exchange, where product names are public, and which has a listing fee.

The private market would be implemented by program, which responds to messages coming to its Nxt address. The buyer sends a message and coins to that address to complete the transaction. The buyer side doesn't necessarily need a specialized program, any Nxt client will do if it can send encrypted messages. (I don't know if the Nxt clients already support that.) Perhaps a more user-friendly buyer-side program would be needed to get users.

If nobody is willing to implement this for a bounty, I can try to do a proof of concept of this myself.

[v39453]

Here are some more thoughts. I'm thinking about private marketplaces on top of the Nxt blockchain. Products are visible only to the users of the marketplace, not to everyone viewing the blockchain.

EDIT: I deleted the previous idea. This is a simplified version. Marketplace name = password.

On the startup screen of the NxtPrivateMarketplace software the user enters the marketplace name, which also acts as a password.

This is less secure than having the program generate the password, but the result of the marketplace name getting found out by outsiders is not as catastrophic as somebody hacking your brainwallet.

[v39453]

The message format would need to be defined, so I'll just make something up. This is the private marketplace version, where the market is visible to those who know the marketplace password.

There can be a FileMarket (selling of files with arbitrary content) and MailOrder (seller sends the product in the mail). I'll begin with the FileMarket because it is easier.

Each message contains a prefix, which is the first 4 bytes of the SHA-256 hash of the marketplace password. Message content is encrypted with AES-256 using the marketplace password, except for the accept message, which should be readable only by the buyer.

Seller declares he sells something by sending himself a message:

sell/product name/description/price/keyword1(optional)/keyword2(optional)/keyword3(optional)/image link (optional, image is encrypted with marketplace password)

Setting keywords allows buyers to find products by searching.

Buyer sends the seller a message to buy:

buy/product name

Seller sends the decryption key for the file to the buyer:

accept/product name/download link/key

If for some reason seller can't complete the transaction:

reject/product name

User sends feedback to the seller:

feedback/product name/score/text

Seller feedback and available products be will be visible on the blockchain to those who know the marketplace password.

EDIT:

Seller sends himself a message to provide general information to the buyers:

seller_info/text/allow other sellers (yes/no)

The first seller can prohibit other sellers from joining the marketplace.

[rdanneskjoldr]

I like the private asset exchange,i also proposed it in the main thread some days ago.
It would only need the possibility to issue an asset with a keypass,and the issuer would give the keypass to whoever he wants.It would be great for internal things in enterprises,or private groups,or things like for example a company issuing ticket-restaurants in a certain zone.

[v39453]

The marketplace creator could act as an administrator, who has the power to ban scammers.

When the marketplace is created, the following message is sent:

market_info/description/seller_fee/buyer_fee

Fees are one-time payments to the administrator to be able to participate in the marketplace. They can also be zero if the administrator so decides.

Administrator sends the following message to ban a user:

ban_account/account_number

Anyone not satistfied with the policies of the administrator can easily create their own marketplace.