Topic: Maximum 0-confirmation TXs (Read 797 times)

The interesting application as far as I can see is not in having clients detect zero-confirmation payments to a given address; it is in having them detect zero-confirmation spends from a given address.

If someone pays for goods with a transaction using a particular set of txin, and In the next ten seconds no other transactions show up in the mempool using any of those same txin, then I am reasonably confident that he's not attempting (or at least will not succeed in) a "double spend" attack.

Because, if it hasn't propagated across the network by ten seconds after I get (and broadcast) my tx, then I assume that because my tx *has* by now propagated across the network, other clients will now refuse to relay any other tx spending the same txins.  

So simply detecting whether a particular txin in a transaction destined for my wallet is spent by any other mempool transaction would be a very rapid way to achieve at least the same degree of certainty on the same schedule that a supermarket gets at the cash register when someone hands them a $20 bill.  Is it counterfeit?  Possibly.  But if the cashier doesn't notice it, the odds are very very low. Likewise, is the coin double-spent?  Possibly, by the time it (doesn't) get into a block.  But if the cashier (or the bitcoin-aware cash register) doesn't notice a competing transaction on the blockchain within ten seconds or less, then the odds are very very low.

well this is interesting I will have a closer look later.

Regards!

I recently made a website about how to check the zero-confirmations immediate tiny-payment security

http://jimmyscratchlab.github.io/check-tinypayment/

I'm not sure what you mean by "processed".

As long as you include a sufficient fee (at least 0.0001 BTC per kilobyte), the transaction doesn't include any dust spam outputs (all outputs are larger than 0.00005640 BTC), you create valid transactions (properly formatted spending unspent outputs with proper signatures), and your client is connected to the network (so that you can send the transaction to the connected peers), then the transaction will be relayed throughout the bitcoin network quickly (typically less than 3 seconds).  As long as the receiver's wallet is online and connected to the bitcoin network, they should see the unconfirmed transaction as soon as it is relayed to them from a peer (typically less than 3 seconds).

So, as long as I am paying fees for all of my TXs they will be immediatley processed and can be seen in the receivers wallet?

Your millions of TX wont propagate unless you pay a fee for each.

Ok, I just want to make sure that the receivers will get and see my million TXs immediatley. There is no need for security through confirmation because I don't attempt to double spend.

Of course you can send as many transactions as you want. But the block that those transactions will appear at is a block at when miners confirm your transactions.

Hi,

how many 0-confirmation transactions can be processed at any time?
Is the amount equal to the amount of TXs fitting in the block?

For example:
There are 100 0-confirmation TXs and the block has only enough space for 20, will the remaining 80 TXs be proccessed and visible for the receiver (but of course not safe) or are they limited to 20 TXs too?

I'm wondering if I can make millions of TXs now, the network processes them immediatly and the miners will confirm the query step by step over several hours or days.