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A man-in-the-middle attack, often abbreviated as an MITM attack, is a type of cyber assault in which an unauthorized individual interposes themselves in the communication flow between two parties who assume they are engaging in direct communication. In this scenario, the attacker gains the ability to intercept, eavesdrop on, and potentially manipulate the content of the communication taking place. Man-in-the-middle attacks pose a significant threat as they allow for clandestine surveillance and potential tampering with communications across various contexts, such as interactions between individuals, clients, and servers, and even secure connections like HTTPS and other SSL/TLS protocols, as well as Wi-Fi network connections, among others.
Here is how a Man-in-the-middle attack works.
Picture a scenario where you and a colleague are engaged in a conversation through a secure messaging platform. In this situation, an adversary with malicious intent aims to intercept your exchange, clandestinely monitor it, and insert fabricated messages into the conversation, making it appear that these false messages are coming from you to your colleague. This form of cyber attack illustrates the peril of a man-in-the-middle assault, where the attacker attempts to undermine the integrity and confidentiality of your communication.
Initially, you request your colleague’s public key to establish secure communication. If your colleague sends her public key, but an attacker manages to intercept it, a man-in-the-middle attack becomes possible. The attacker sends you a fabricated message skillfully designed to mimic your colleague’s communication. However, this message contains the attacker’s public key instead of your colleague’s legitimate one. Thinking you are using your colleague’s public key, you encrypt your message and unknowingly employ the attacker’s key to secure it. Subsequently, you send this encrypted message back to what you believe is your “colleague.”The attacker, once again, intercepts the message, decrypts it using their private key, manipulates the content, and then re-encrypts it using the public key they initially intercepted from your colleague, who had intended to send it to you. As your colleague receives and examines the encrypted message, she is under the impression that it originated from you, unaware of the attacker’s meddling.