jakiro
Author: Zhixiong Pan
You actually have a “hardware wallet” in your pocket for a long time
The mobile phones and computers we use every day actually have specialized security chips built into them.For example, the “Secure Enclave” in the iPhone, or the Keystore / Trust Zone / StrongBox in the Android phone.
This separate physical area is often called a TEE (Trusted Execution Environment).Its characteristic is “only in and out”: the private key is generated inside and will never leave this physical area. The outside can only request it to sign data.
This is actually the standard for hardware wallets.When signing, these chips generally use an industry standard algorithm curve selected by NIST (National Institute of Standards and Technology): secp256r1.This is the cornerstone behind WebAuthn and FIDO2 (like your fingerprint login, FaceID).
Just one letter difference
Embarrassingly, Ethereum does not natively support this mainstream secp256r1.
At that time, the Bitcoin community chose the relatively unpopular secp256k1 out of concerns that the NIST curve might have a “national backdoor.” Therefore, Ethereum followed the tradition of this curve when designing the account system.
Although r1 and k1 appear to differ by only one letter, mathematically they are two completely different languages.This leads to a huge pain point: the security chip in your mobile phone is confused about Ethereum, and it cannot directly sign Ethereum transactions.
Since the hardware cannot be changed, then this version will be “compatible” with it.
Ethereum obviously cannot force Apple or Samsung to change the chip design to adapt to secp256k1. The only way is for Ethereum to adapt to secp256r1.
Is it possible to use smart contracts to write code to verify the r1 signature?It works in theory, but the mathematical operations are too complex, and running a verification may consume hundreds of thousands of gas, which is completely unavailable economically.
Therefore, in the Fusaka upgrade, the developers introduced a killer weapon: Precompile.This is equivalent to opening a “backdoor” or “plug-in” in the Ethereum Virtual Machine (EVM).Instead of letting the EVM calculate it step by step, it is better to write this verification function directly into the underlying code of the client.Developers only need to call a specific address to complete verification at very low cost.
In EIP-7951, this cost is fixed at 6900 Gas, which is directly reduced from hundreds of thousands to several thousand, and finally enters the range of “can be used daily in real products”.
The final piece of the account abstraction puzzle
The implementation of this EIP means that we can finally sign and authorize smart accounts on Ethereum in the TEE environment of mobile phones.
It should be noted that this does not apply to EOA addresses such as your current MetaMask (because their public key generation logic is still k1).
It is specially prepared for “Account Abstraction” (AA wallet).In the future, your wallet will no longer be a string of mnemonic words, but a smart contract.The contract says:
“As long as the fingerprint (r1 signature) is verified to be correct, the transfer will be allowed.”
Summary
EIP-7951 may not make mnemonics disappear overnight, but it finally removes the biggest stumbling block on the road to mass adoption of Ethereum.
Before that, users were always faced with a cruel multiple-choice question: Do you want to have “bank-level” autonomous security?You have to spend money on a OneKey, Keystone or Ledger, and you have to keep your mnemonic words like gold bars; want the smoothest experience?You can only store coins on exchanges or custodial wallets, at the cost of handing over control (sacrifice of decentralization).
After the Fusaka upgrade, this multiple-choice question will no longer exist.
With the implementation of EIP-7951, “mobile phones as hardware wallets” will gradually become a reality.For the billion new users in the future, they may not need to know what a “private key” is, nor will they need to face the psychological pressure of transcribing 12 words.
They only need to swipe their face and press their fingerprints like they usually do when buying coffee, and the iPhone security chip on the back will call secp256r1 to sign the transaction and complete the verification through Ethereum’s native precompiled contract.
This is the correct posture for Ethereum to embrace the next billion users: instead of arrogantly asking users to learn complex cryptography, it should put down its posture to be compatible with the universal standards of the Internet and actively enter users’ pockets.
