255 transactions is a good number.  255 fits 8 bits and 255 * 128 b fits 32 Kb.


UPDATE

Added a button to generate authorization tokens that can be used on third-party websites.  Such token identifies an account owner and removes necessity in registration.  Using a token any website can get the account id (for withdrawals and other needs) and make sure that a user is the legitimate owner of the account.

Authorization workflow
1]  Unlock an account in Nxt client
2]  Press KEY button and enter the website url
3]  Copy a token (160 chars) and paste it on the website to log in

I'm working on blockchain synchronization and have to decide the maximum number of transactions in a single block.  I think that a small number will lead to fee competition, which is good for miners but bad for users.  Any suggestions?

UPDATE

A version with working MY TRANSACTIONS section deployed.  Now you can see the history of your transactions.  The blockchain was reseted to block 0.

P.S.  http://88.198.210.245:7875

No, higher dispercy of coins = higher odds to generate a block.  With 10 accounts holding 100 mil coins each the base target should be 76.8%

I see someone is adding transactions non-stop.  Is it a stress-testing or a DoS attack?

There will be 1,000,000,000 coins.  And amounts can be only whole numbers.  Later we can add fractional numbers but now it would be inconvenient.

Estimated time changes each block due to retargetting and different block hashes.  10'000 NXT gives you 0.001% to generate a block.

UPDATE

A version with mining is deployed.  Visit http://88.198.210.245:7875 and open BLOCKS widget.  Use any digit as a secret phrase to unlock one of the funded accounts and send some money to your own account (limited to 10,000 at once).  After a confirmation you will be able to generate blocks as well.

Now we are testing the retargetting.  100 % base target equals to the target that lets to generate one block per minute with 1,000,000,000 coins on the balance.  Actual generation time is displayed on BLOCKS widget in RECENT BLOCKS section.

Anyone can test it.

I have done with the mining.  Tomorrow I will have it implemented in the web client and you will be able to watch the blockchain growing.

UPDATE

Added transaction handling.  At http://88.198.210.245:7875/ you can see how it's implemented in the interface.

How to send money
1]  Go to http://88.198.210.245:7875/
2]  Click the orange lock to unlock an account
3]  Enter any digit into SECRET PHRASE field, for example "1" (the genesis block contains only 10 addresses with 100 mil coins on each)
4]  Click the purple arrow in the top right corner
5]  Fill the form, amount must be not greater than 10,000 and fee not greater than 100 (limited for testing)
6]  Deadline (in hours) can be less than 1, enter 0.1 to set it to 6 minutes
7]  See the balance adjusted and the transaction appearing in the unconfirmed transactions list

If a transaction is not included into a block (it's not because mining is in development yet) then after the deadline is reached it will be removed.  We tested that transactions are correctly propagated over the network (sent some from one peer and watched them appearing on another).

Now I'm working on the most interesting part -- the mining.  Stay tuned.

I asked the support of one exchange.  They said Nxt API is non-standard, not like cookie cutter altcoin JSON-RPC API, and requires some effort to add it to the exchange.  Also I don't want Nxt to become just another pump-n-dump altcoin, Bitcoin-to-Nxt-and-back gateway is more preferable.  I'll think of it later.

I can not afford to spend 100 BTC.  What about 20 BTC for the exchange?

We need someone to launch services available shortly after the Nxt launch.  An exchange, a gambling site, a faucet, etc.  Post in this thread your offer (what service, when planning to open and how much in bitcoins you want as a bounty).  Feel free to ask anything about Nxt API.

Nxt doesn't need 4000 BTC for a huge success, it needs 4000 participants.  I agree that critical mass is important, not sure about an early adopter bonus though.  First let's get something working.


To keep you updated, here are some technical details:

Address length - 8 B (max 20 chars in human-readable notation)
Private key length - 32 B
Public key length - 32 B
Signature - 64 B
Block header length - 192 B
Transaction length - 128 B

Each transaction has "deadline" value to limit time it can be added into a block.  Days when you send a transaction and wait a whole day to get it confirmed have gone for good.  Now you can set deadline to 5 minutes and if it's not confirmed then resend it with a higher fee.
Also each transaction can be marked with "id" (8 B length) to help merchants to identify your payment.  Not necessary to create a separate address for each customer anymore.

Let me cite Bitcoin Magazine (http://bitcoinmagazine.com/6528/what-proof-of-stake-is-and-why-it-matters/)

After thinking about the mining algorithm I came to conclusion that original proof-of-stake used by PPC and NVC is a bit flawed.  Bob could accumulate small amounts on different accounts during a long period of time and then attempt a 51% attack.  Artificial limits like max 90 days don't seem to work as intended.  Nxt will use a different proof-of-stake approach, I need time to nail some details and then I'll post them here.

Important note

I decided to use Ed25519 instead of the standard Java ECDSA.  It means that "naig.class" shouldn't be used for vanity address generation anymore.  But you can use Nxt web client to choose a cool-looking address.  The client is being developed so account locking/unlocking and peer handling are the only features implemented yet.

At the moment only one boot-strapping server is available:  http://88.198.210.245:7875

How to generate an address:
1]  Visit http://88.198.210.245:7875
2]  Click on the orange lock in the top left corner
3]  Type a secret phrase, later it will be used to unlock your account
4]  Hit OK button
5]  The address will appear next to the lock icon


PM me if you can contribute to the project development by providing a server that will be used as a boot-strapping node.

I created a small program for address generation.  https://mega.co.nz/#!94IETDZL!FRbFAnAi4uu4G5dh6HUSvmHfgK5GXKsh4NWdgY2avJ0

How to use it

1]  Download "naig.class" file
2]  Type "java -cp . naig SECRET_PHRASE"

You must have Java RE installed.

The secret phrase should be very long, it will be truncated to the first 100 chars though.  You'll get a number that can be used to receive coins (address).  Number's length may vary from 1 to 20 chars depending on the secret phrase.  While you are waiting for the release you can try to generate a short memorable address

I like competition.  You should do the phasing by the end of this year otherwise you won't be the first PoS only crypto.

https://bitcointalk.org/index.php?topic=303898.0