Man-In-The-Middle Attack AKA MITM
It is an attack where the attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other.
Countermeasures
• Digital Signature - A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents.
• Mutual authentication - Mutual authentication, also known as two-way authentication, is a security process in which entities authenticate each other before actual communication occurs.