Quote from: Craigmartin on December 05, 2018, 07:36:34 AM

Hi guys

I have 3 questions.
(1) How is it possible to send ERC20 Tokens without gas?
(2) If I want to send ERC20 Tokens from, lets say Account A with 0 Ethereum to Account B with Ethereum and have account B pay for the transaction gas, how do I do that?
(3) How is this guy in the examples doing it and is the gas being paid and by which account, the sender or receiver?

To me it looks like no gas is being paid, which is very strange.

I've tried googling answers to this but I'm getting the same answers "It's Not Possible you Noob""

Ok, First of all I will tell you that this is a bitcoin forum, and this post should be in Altcoin discussion session.

For your questions, first of all you need to understand that ethereum is a "world computer", where everything is proceessed by the whole network. So, if it was possible to make a zero gas transaction, that would easily result in a dos attack (denial of service).

For example, someone would create a script of infinity transactions in a loop, until the network goes down.
What prevents a DOS attack in ethereum Network is that everything costs gas. So you have to pay for everything you do in the network.

So, the whole gas system was created in such a way to prevent this from happening. As gavin wood said, in a world computer, waste of computer resources would mean waste of world resources.

Regarding your example, you can see that the user spent 37263 gas. However, the gas prices was set to zero. I believe there are two possible explainations for that:
1- the gas price is not zero (0.000000), but something so low that etherscan consider as zero, such as 0.00000001 eth .
2- the owner of the transaction is a miner, and he decided to include this transaction in a block anyway. . I am not sure if that is possible in ethereum network, but it MAY be.

I made this post explaining ethereum gas system some time ago:
https://bitcointalk.org/index.php?topic=3285767.msg34270190#msg34270190

You cannot control how much gas is necessary to make a transaction. If you set a low gas for a transaction, it won't be processed. What you can set is the gas PRICE, which is , in this case, low. I don't believe it is zero, but so low that etherscan cannot see it.

As you can see, he paid a lot of gas for this transaction. Who decides how much is the minimum acceptable gas price is the miner.