Adam Back claims to have warned Ethereum’s early developers against an architecture he considered flawed. However, no easily verifiable public evidence establishes that he sent them a specifi
Adam Back claims to have warned Ethereum’s early developers against an architecture he considered flawed. However, no easily verifiable public evidence establishes that he sent them a specific warning about the now criticized account model before the network’s launch.
The CEO of Blockstream reignited the debate between Bitcoin and Ethereum in a message published on October 10. There, he defends the UTXO model chosen by Satoshi Nakamoto and fiercely criticizes the early Ethereum designers’ experiment.
Your 1st cryptos with CoinbaseThis link uses an affiliate program.“It’s almost like Satoshi knew distributed systems”, Adam Back wrote. He then states that Ethereum developers were “young, naive” and lacked the necessary experience when they built the network around an architecture he considers “manifestly flawed”.
His message ends with an important statement: “I tried to warn them”. However, Back does not provide any link, date, or copy of an exchange to identify this warning.
Public archives show he has criticized Ethereum for several years. In 2019, he was already comparing the project to Theranos. In August 2020, he grouped Ethereum with Bitconnect, OneCoin, and other controversial projects before denouncing the presale of part of the ETH.
These positions confirm his long-standing opposition to Ethereum. Nonetheless, they do not prove that he warned its founders about the specific issues associated today with its architecture before the blockchain launch in July 2015.
Bitcoin uses the UTXO model, standing for “unspent transaction outputs”. Its operation can be compared to bills: a transaction consumes existing units and creates new outputs that their owners can spend later.
Ethereum relies on accounts whose balances 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 easier parallel processing of certain independent transactions. It also limits the amount of state shared among users and applications. Conversely, the account system offers greater flexibility for building financial protocols and complex applications.
Presenting one as objectively correct and the other as necessarily “broken” therefore involves a technical and political judgment. Ethereum has operated for more than eleven years and secures hundreds of billions of dollars in assets, even if its architecture brings challenges related to state growth, concurrent transactions, and contract complexity.
Network developers are also studying mechanisms that reclaim some advantages of UTXOs. EIP-8141 would notably propose a new transaction format to improve account abstraction and prepare for the adoption of more resilient signature systems.
Adam Back’s statement responds to a warning issued by Justin Drake, an Ethereum Foundation researcher. Drake 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 “within months, not years”. Therefore, Drake recommends gradually preparing the transfer of funds to addresses whose public key has never been exposed.
However, no practical attack of this type has yet been demonstrated. Yehuda Lindell, head of cryptography at Coinbase, has stated that there is currently no indication of a weakening of the mathematical assumptions protecting these signatures.
More importantly, 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 did exist to retrieve a private key from an exposed public key, both networks would be affected.
The UTXO model nevertheless offers Bitcoin a practical advantage: best practices encourage generating a new address after each payment, which can reduce public key exposure. This advantage disappears when users reuse their addresses.
Adam Back holds genuine 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 whitepaper.
This expertise is nevertheless insufficient to retrospectively confirm his claim. In the absence of dated archives, it remains impossible to establish to whom Back addressed his warning, when, and about which specific risk.
The most rigorous conclusion remains nuanced: Adam Back has criticized Ethereum for a long time, but his claim of having warned its creators against their account model remains publicly unsubstantiated.
