Eavesdropping

Eavesdropping in the cybersecurity world is a type of malicious attack where data is redirected to a third party as it passes over the wire. The wire could be located on a local network or the internet. Data eavesdropping is the main catalyst for the internet increasing its use of encryption. Encrypting data across the wire protects individuals and businesses from eavesdropping provided that the cipher algorithm is cryptographically secure.

Address Resolution Protocol (ARP) poisoning is often used in data eavesdropping. Users connect to the internet from a local network using their own devices, and each user device broadcasts their IP address associated with their network card’s MAC (Media Access Control) address. Attackers use ARP to broadcast their own device MAC address to the local network’s default gateway, forcing user devices to connect to the attacker-controlled device when making web requests. Attackers intercept network traffic, eavesdrop on data, and then redirect the request to the intended recipient server. The man-in-the-middle (MitM) approach to eavesdropping is the most common way to steal user data, especially on public Wi-Fi networks. MitM attacks are silent and completely unknown to users working on the local network.

Any data sent over a wire can be disclosed to a third party. Encryption scrambles data so that it cannot be deciphered. Eavesdropping isn’t always done purposely. Data could be logged in plaintext as it moves from network to network. Cybersecurity and activity logs are common across the internet, so sensitive data in plaintext could be recorded as it transmits from a source to the intended destination. These logs are vulnerable to theft, so any compromise of the third-party network could result in your sensitive data being exposed.

Encryption remedies many of the risks associated with transmitting plaintext sensitive data across the internet and eavesdropping attacks. Several encryption algorithms are available, but you should choose a current cryptographically secure cipher algorithm. When data is encrypted and sent to a destination, encryption makes it impossible to read. Should an attacker perform a MitM or obtain data logs, the information would be unreadable, assuming that the data was encrypted with a cryptographically secure cipher algorithm.

For corporations, eavesdropping is especially dangerous for remote employees and employees connecting to the local network from a public Wi-Fi. Some attackers set up fraudulent Wi-Fi hotspots to trick users into connecting to it. Attackers using a malicious hotspot can also eavesdrop on data sent from user devices while connected to it. To combat this type of eavesdropping, enterprise administrators can have users first connect to a VPN before sending data to the local environment. Using a virtual private network (VPN), data is encrypted and protected as it passes over the internet. It protects from eavesdropping when an attacker performs a MitM or employees wrongly connect to a malicious hotspot on an attacker-controlled device.

Users should always connect to servers using SSL/TLS connections to automatically encrypt data. Internal servers can also use SSL/TLS to protect from eavesdropping on the local environment. For added protection, corporations can use VPN and SSL/TLS for any remote users.

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Related Terms

• Man-in-the-Middle (MitM)
• Virtual Private Network (VPN)
• Unencrypted Traffic

Further Reading

• Why Your Users and Clients Should Encrypt Emails
• Most Common Wireless Network Attacks
• Protect from Eavesdropping with Email Encryption Gateway

How Can TitanHQ Help?

TitanHQ’s Email Encryption Solution encrypts sensitive email content, ensuring that only the intended recipients can read the message, preventing eavesdropping during email transmission.