Are Quantum Computers an Urgent Threat to Bitcoin?

Recently, notable developments in the cryptocurrency market include potential long-term threats to Bitcoin (BTC). Nic Carter, co-founder of Coin Metrics, stated that the biggest risk to Bitcoin's fundamental cryptographic structure comes from quantum computers, describing this situation as "not science fiction, but an urgent priority."

Carter explained the functioning of Bitcoin's private key system in simple terms. He noted that users generate a public key based on a specific number they choose using the secp256k1 curve. He emphasized that Bitcoin's security relies on the one-way nature of this process, meaning it is "easy to go forward but impossible to go back." He likened this mathematical structure to a "massive number shuffler," explaining that the conversion of public keys to private keys can be efficiently accomplished using the "double and add" method, yet the reverse operation is practically impossible with classical computers.

According to Carter, the primary concern is the progress of quantum computers in solving the discrete logarithm problem, which underpins Bitcoin signatures. If this threat becomes a reality, it may one day be possible to derive private keys from public keys. The visibility of public keys in the blockchain with every transaction increases this risk. Although this conversion is practically impossible today, he warns that reusing addresses could lead to keys being exposed for longer periods, creating future risks.

Carter views this situation not as a call for panic, but as a necessity for planning. He pointed out that avoiding address reuse is the simplest security measure in the short term, while in the long term, the development of quantum-resistant signature algorithms and prioritizing appropriate transition plans are essential. Carter, who published the first part of the series, announced in a statement on X that he will focus on "post-quantum break scenarios" in the second and third parts.