Ethereum: Adam Back accuses its creators of ignoring his warnings

Adam Back claims to have warned the early developers of Ethereum about an architecture he deemed flawed. However, there is no easily verifiable public evidence that he had issued them a specific warning regarding the criticized account model before the network's launch.

In brief

• Adam Back claims to have warned the early developers of Ethereum about the weaknesses of its architecture, without providing public proof.
• The UTXO model of Bitcoin and the account system of Ethereum each have their advantages and limitations.
• Concerns regarding the security of cryptographic signatures affect both Bitcoin and Ethereum.
• Despite his longstanding criticisms, Adam Back has not demonstrated that he alerted the founders of Ethereum before its launch.

Adam Back attacks Ethereum's foundational choices

The CEO of Blockstream reignited the debate between Bitcoin and Ethereum in a message published on October 10. He defends the UTXO model chosen by Satoshi Nakamoto and directly criticizes the experience of Ethereum's early designers. Your first cryptos with Coinbase This link uses an affiliate program

<< It’s almost as if Satoshi understood distributed systems >>, Adam Back wrote. He then claims that the Ethereum developers were << young, naive >> and lacked the necessary experience when they built the network around an architecture he considers << manifestly flawed >>.

His message concludes with an important assertion: << I tried to warn them >>. However, Back provides neither a link, nor a date, nor a copy of an exchange that would identify this warning.

Public archives show that he has been criticizing Ethereum for several years. In 2019, he already compared the project to Theranos. In August 2020, he placed Ethereum alongside Bitconnect, OneCoin, and other controversial projects, before denouncing the presale of some ETH.

These positions confirm his longstanding opposition to Ethereum. However, they do not prove that he warned its founders before the blockchain's launch in July 2015 about the specific problems he now associates with its architecture.

UTXO and accounts respond to two different conceptions

Bitcoin uses the UTXO model, for << unspent transaction outputs >>. Its operation can be compared to that of banknotes: a transaction consumes existing units and creates new outputs that their owner can spend later.

Ethereum relies on accounts whose balance and state evolve with each operation. This structure facilitates the execution of smart contracts, as applications can store and modify information directly on the blockchain.

The UTXO model allows for easier processing of certain independent transactions in parallel. It also limits the amount of state shared between users and applications. The account system, on the other hand, offers more flexibility for building financial protocols and complex applications.

Presenting one as objectively correct and the other as necessarily << broken >> is therefore a technical and political judgment. Ethereum has been operating for over eleven years and secures hundreds of billions of dollars in assets, even though its architecture leads to difficulties related to state growth, concurrent transactions, and contract complexity.

Developers of the network are also studying mechanisms that take back some advantages of UTXO. EIP-8141 would notably propose a new transaction format to improve account abstraction and prepare for the adoption of more resilient signature systems.

The Cryptographic Threat Also Concerns Bitcoin

Adam Back's statement responds to the warning issued by Justin Drake, a researcher at the Ethereum Foundation. He believes that advances in artificial intelligence could accelerate the discovery of methods capable of weakening elliptic curve cryptography.

In his most pessimistic scenario, an attack could become feasible << in a few months, not in a few years >>. Drake therefore recommends gradually preparing the transfer of funds to addresses whose public key has never been exposed.

However, no practical attack of this type has been demonstrated. Yehuda Lindell, head of cryptography at Coinbase, has notably stated that there is currently no evidence showing a weakening of the mathematical assumptions that protect these signatures.

Moreover, the choice between UTXO and accounts does not alone resolve this threat. Both Bitcoin and Ethereum use the ECDSA algorithm to authorize certain transactions. If a method were to actually allow the recovery of a private key from an exposed public key, both networks would be affected.

The UTXO model, however, provides a practical advantage to Bitcoin: best practices encourage the creation of a new address after each payment, which can reduce the exposure of public keys. This advantage disappears when users reuse their addresses.

An Old Critique, but an Unproven Warning

Adam Back has real legitimacy in the history of cryptography. His Hashcash system, presented in 1997, inspired Bitcoin's proof-of-work mechanism. Satoshi Nakamoto also cited him in the network's white paper.

However, this expertise is not enough to retrospectively confirm his claim. In the absence of dated records, it remains impossible to establish to whom Back would have addressed his warning, when, and on what specific risk.

The most rigorous conclusion remains nuanced: Adam Back has long criticized Ethereum, but his claim that he warned its creators against their account model remains publicly unsubstantiated.