Ethereum: Why Spendable and Solvable Outputs Are Fake
In the world of blockchain technology, especially Ethereum, the concept of spendable and solvable outcomes can be misleading. As a developer or researcher familiar with the Ethereum ecosystem, it is essential to understand what these terms mean and why they may seem fake.
What are Spendable and Solvable Outputs?
In Ethereum, a transaction is considered “spendable” when its outcome is redeemable for Ether (ETH) at a rate of one ETH per unit. In other words, an outcome can be spent on something in exchange for a certain amount of ETH. The ability of that output to be spendable determines whether it has value or utility.
In contrast, an output is considered “solvable” when its weight (i.e., the number of gas units required to call a function) is solvable by the Ethereum Virtual Machine (EVM). Solvency refers to whether the function’s gas limit can be satisfied within the transaction’s execution time. When an output has both spendable and resolvable properties, it means that:
- Spendable: The output cannot be directly spent in ETH without additional processing or action.
- Resolvable: The output weight is within the EVM’s gas limit, allowing it to function.
Why are both spendable and resolvable outputs false?
The reason why inputs (i.e. the “spendable” part) may appear false is because they have been removed from the transaction. In Ethereum, when a transaction includes an input, it means that the output has already been spent or has no value. This is because transactions are designed to be one-way: once the transaction is executed, the inputs and outputs are no longer “spendable” in the traditional sense.
On the other hand, the resolvable property of an output can still be preserved even if its input is removed by the transaction. For example, if a function call has been optimized or cached by the EVM to reduce gas consumption, it can still be executed with the same weight (i.e., solvable). This does not mean, however, that the original result was “spendable.”
What does this mean for developers and users?
If you encounter an Ethereum transaction that appears to have a spendable but non-resolvable output, there are several possibilities:
- The function has been optimized: The function call may have been rewritten to reduce gas consumption, making it more efficient to execute.
- Gas limit was increased
: The user or developer may have manually increased the EVM gas limit on an input or function call to account for optimization or caching.
- Transaction is incomplete: In some cases, a transaction may be partially executed without including all necessary inputs or outputs.
To check if a specific output is spendable and resolvable in Ethereum:
- Check the transaction details: look at the “txid” field to make sure the input was removed from the transaction.
- Check the function name and parameters: make sure the function call was not optimized for caching or other purposes.
- Use tools like “ethers.js” or “eth-abi” to inspect the gas consumption and weights of the EVM output.
In conclusion, Ethereum’s spendable and solvable results can appear to be wrong for various reasons, such as function optimizations or increased gas limits. Developers and users should be aware of these nuances when working with transactions in this ecosystem.