EIP-2029: State Rent A - State counters contract


  Ethereum Improvement Proposals
        
        
          
            
              
            
          
        

        AllCoreNetworkingInterfaceERCMetaInformational

      



      
        
  
    

  
    
      🚧 Stagnant
    
    
    
    
    
      Standards Track: Core
    
  
  
    
      EIP-2029: State Rent A - State counters contract
    
    
      
        
      
    
    
      
        
      
    
  

  

  	Authors	Alexey Akhunov (@AlexeyAkhunov)
	Created	2019-05-15
	Discussion Link	https://ethereum-magicians.org/t/eip-2029-state-counters-contract-change-a-from-state-rent-v3-proposal/3279


  


  

  
    Table of Contents

    	Simple Summary
	Abstract
	Motivation
	Specification
	Rationale
	Backwards Compatibility
	Test Cases
	Implementation
	Copyright



  


  
      
      
         Simple Summary
      
      
    

A smart contract is deployed on all Ethereum networks, at a pre-determined address, with the code that simply reads the slot in its storage specified by the
only parameter. Later, this contract becomes “special” in that Ethereum start writing state counters (number of total transactions, number of accounts,
etc.) into that contract.

  
    
      
      
         Abstract
      
      
    

This is part of the State Rent roadmap. This particular change introduces a place in the Ethereum state where various state counters can be stored. At this
point, the most important counter is the total number of transactions happened, and this counter will be used to populate the nonces of newly created
non-contract accounts. This way of populating nonce ensures replay protection for accounts that were evicted and then brought back by sending ether to them.

  
    
      
      
         Motivation
      
      
    

Ethereum currently does not have a special place in the state for tracking state counters such as number of transactions or number of accounts.

  
    
      
      
         Specification
      
      
    

Prior to the block A, a contract is deployed with the following code:
0x60 0x20 0x60 0x00 0x80 0x80 0x35 0x54 0x90 0x52 0xF3, which corresponds to this assembly:
PUSH1 32 PUSH1 0 DUP1 DUP1 CALLDATALOAD SLOAD SWAP1 MSTORE RETURN
Call to this contract accepts one 32-byte argument, x, and returns the value of the storage item [x].


This contract is deployed using CREATE2 opcode in such a way that it has the same address on any network.

  
    
      
      
         Rationale
      
      
    

Two alternative solutions were considered so far:

	Extending the structure of the Ethereum state to introduce more fields, and hence change the way the state root is constructed. The main downside of this
approach is the impact on the software what is currently coupled with the particular way the state root is constructed. Particularly it affects the software
that deals with merkle proofs derived from the state root.
	Extended State Oracle (EIP-2014). Under such proposal, there will be a precompile contract with standardised interface, capable of returning
current values of the counters. However, the actual data being returned by such oracle is not explicitly in the state, and is not Merkelised. It means that all the counters need to be added to the snapshots when the snapshot sync is perform, so they still present in the state, but implicitly.


  
    
      
      
         Backwards Compatibility
      
      
    

This change is backwards compatible and does not require hard fork to be activated.

  
    
      
      
         Test Cases
      
      
    

Tests cases will be created to ensure that the state counter contract returns its storage items correctly.

  
    
      
      
         Implementation
      
      
    

Implementation is envisaged as a transaction that can be posted from any Ethereum address and will cause the deployment of the state counter contract.

  
    
      
      
         Copyright
      
      
    

Copyright and related rights waived via CC0.


  Citation

  Please cite this document as:

  
  Alexey Akhunov (@AlexeyAkhunov), "EIP-2029: State Rent A - State counters contract [DRAFT]," Ethereum Improvement Proposals, no. 2029, May 2019. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-2029.






      
    
  

  

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        Ethereum Improvement Proposals (EIPs) describe standards for the Ethereum platform, including core protocol specifications, client APIs, and contract standards.