Whitepaper - Ethereum Classic With Cover

Ethereum Classic Documentation, Release 0.1
Example transaction cost
Let’s take a contract that just adds 2 numbers. The EVM OPCODE ADD consumes 3 gas.
The approximate cost, using the default gas price (as of January 2016), would be:
3 * 0.05e12 = 1.5e11 wei
Since 1 Ether is 1e18 wei, the total cost would be 0.00000015 Ether.
This is a simplification since it ignores some costs, such as the cost of passing the 2 numbers to contract, before
they can even be added.
• question
• gas fees
• gas cost calculator
• Ethereum Gas Prices
Operation Name Gas Cost Remark
step 1 default amount per execution cycle
stop 0 free
suicide 0 free
sha3 20
sload 20 get from permanent storage
sstore 100 put into permanent storage
balance 20
create 100 contract creation
call 20 initiating a read-only call
memory 1 every additional word when expanding memory
txdata 5 every byte of data or code for a transaction
transaction 500 base fee transaction
contract creation 53000 changed in homestead from 21000
Account interactions example - betting contract
As previously mentioned, there are two types of accounts:
• Externally owned account (EOAs): an account controlled by a private key, and if you own the private key
associated with the EOA you have the ability to send ether and messages from it.
• Contract: an account that has its own code, and is controlled by code.
By default, the Ethereum execution environment is lifeless; nothing happens and the state of every account remains
the same. However, any user can trigger an action by sending a transaction from an externally owned account,
setting Ethereum’s wheels in motion. If the destination of the transaction is another EOA, then the transaction
may transfer some ether but otherwise does nothing. However, if the destination is a contract, then the contract in
turn activates, and automatically runs its code.
The code has the ability to read/write to its own internal storage (a database mapping 32-byte keys to 32-byte
values), read the storage of the received message, and send messages to other contracts, triggering their execution
in turn. Once execution stops, and all sub-executions triggered by a message sent by a contract stop (this all
happens in a deterministic and synchronous order, ie. a sub-call completes fully before the parent call goes any
further), the execution environment halts once again, until woken by the next transaction.
Contracts generally serve four purposes:
• Maintain a data store representing something which is useful to either other contracts or to the outside world;
one example of this is a contract that simulates a currency, and another is a contract that records membership
in a particular organization.
76 Chapter 1. Contents