The development of true quantum computers is an active area of research and holds great potential for solving complex problems more efficiently than classical computers. While it is difficult to predict the exact timeline for achieving true quantum computers, there has been significant progress in recent years.
Regarding their impact on blockchains like Bitcoin, it is important to note that the security of blockchain systems relies on cryptographic algorithms, such as the ones used for digital signatures and encryption. These algorithms are designed to be resistant to attacks from classical computers, but they could be vulnerable to attacks from quantum computers in the future.
Quantum computers have the potential to break certain cryptographic algorithms that are commonly used in blockchain technology, such as the elliptic curve digital signature algorithm (ECDSA) used in Bitcoin. This could potentially allow an attacker with a powerful enough quantum computer to forge transactions or steal private keys.
However, it's worth mentioning that the development of quantum-resistant cryptographic algorithms is also an active area of research. These algorithms are designed to withstand attacks from both classical and quantum computers, ensuring the security of blockchain systems in a post-quantum world.
To summarize, while true quantum computers have the potential to break certain cryptographic algorithms used in blockchains like Bitcoin, ongoing research is focused on developing quantum-resistant cryptographic algorithms to safeguard against such attacks.