Bitcoin network sees spike in IP addresses, raising concerns over potential Sybil attack

Bitcoin's peer-to-peer network experienced a sharp rise in unique IP addresses shared via ADDR messages, jumping from under 65,000 to around 250,000 daily since mid-April 2026. This surge has raised concerns from developer Jameson Lopp about a possible Sybil attack, where fake nodes flood the network to gain influence. However, experts note other explanations like real node growth, IP rotation, or surveillance efforts could also explain the spike. Bitcoin Core has protections against such attacks, but no system is fully immune, keeping the situation under close watch.