Eclipsing Bitcoin Nodes with BGP Interception Attacks

Authentication plays a pivotal role in thwarting attackers who attempt to impersonate unauthenticated connections or interfere with new ones during the handshake process. While it's true that an attacker could still intercept existing authenticated connections, they wouldn't be able to inspect the traffic due to the protections authentication provides. A significant advantage of the countersign approach over other authentication schemes is its invisibility to potential man-in-the-middle (MITM) attackers. This obscurity forces attackers to choose between risking detection or abstaining from interfering with traffic, especially once the method gains minimal usage.

Countersign envisions a scenario where a node involved in a transaction employs good security practices by establishing authenticated connections with several peers. This strategy involves treating transactions with insufficient confirmation depth as unconfirmed if many of these authenticated peers become unreachable. This method aims to prevent attackers from exploiting network partitions to conduct fraudulent transactions by isolating a portion of the network with the majority hash power.

The concept of diversity in network observation points offers another layer of security. By having multiple entities run observation points and publish signed messages about what they believe to be the leading chain tips, it provides a varied perspective on the network's state. Although these observations cannot directly influence consensus decisions—due to the risk of creating vulnerabilities such as block censorship—they can enhance the network's safety. Specifically, they can help in considering transactions as unconfirmed in the absence of recent or reliable observations, thereby contributing to a more secure and resilient network infrastructure.