Certified: The Security+ Prepcast

In this episode, we are diving deeper into encryption, one of the most vital tools in cybersecurity. Encryption protects information by converting it into an unreadable format that can only be accessed with the correct key. It is used in everything from full-disk security to real-time web browsing. Understanding encryption at different levels and knowing how various techniques apply in real-world settings will prepare you for both the Security Plus exam and future roles in cybersecurity.
Let’s start with encryption levels and types. One of the most widely used methods is full-disk encryption. This approach secures the entire storage medium—every file, every folder, and even the operating system itself. Full-disk encryption protects data at rest, meaning data stored on a physical device. If someone steals a laptop with full-disk encryption enabled, they will not be able to access the data without the correct credentials or decryption key.
Next is partition-level encryption. This method targets a specific partition on a disk rather than the entire drive. This can be useful when different types of data reside on separate partitions, and you only want to protect sensitive sections. For example, a dual-boot system may encrypt the partition containing company records while leaving a public operating system unencrypted.
Then we have file-level encryption. This protects individual files, allowing greater flexibility. A user can encrypt personal tax documents without affecting the rest of their system. File-level encryption is often used in cloud storage solutions, where only specific files are sensitive. Volume-level encryption is similar, but applies to a group of files treated as a single unit, like a secure folder or mounted drive.
Database and record-level encryption go even further. These methods protect either the entire database or specific records within it. For example, an e-commerce site might encrypt only credit card data while leaving public product information in plain text. These forms of encryption are useful when performance is a concern and only certain parts of the data need protection.
Now let’s move to transport and communication encryption. While encryption at rest protects stored data, transport encryption protects data as it moves across networks. One of the most common methods is Secure Sockets Layer and its successor, Transport Layer Security. These protocols encrypt data exchanged between clients and servers, such as during online banking, shopping, or logging into webmail. When you see a padlock icon in your browser, that means Secure Sockets Layer or Transport Layer Security is active.
Another critical protocol is Internet Protocol Security, often called I P Sec. This is a framework used to secure communication at the network layer. It is commonly used in virtual private networks, or V P Ns, where secure tunnels are established between endpoints to protect sensitive data from being intercepted during transmission.
Real-world case studies prove the value of transport encryption. In one major breach, attackers intercepted unencrypted communications between point-of-sale terminals and a central server. Credit card numbers were stolen in real time. Afterward, the company implemented full Transport Layer Security across the network, eliminating the exposure. In contrast, companies that had secure tunnels in place during similar attacks were able to protect customer data, avoid fines, and maintain trust.
Now let’s explore symmetric versus asymmetric encryption. Symmetric encryption uses a single key to both encrypt and decrypt data. This makes it fast and efficient, which is why it is commonly used for encrypting large volumes of data. However, both parties must have access to the same key, which creates a key distribution challenge. If the key is intercepted, the entire system is compromised.
Asymmetric encryption solves the key distribution problem by using a pair of keys—one public and one private. The public key encrypts the data, and the private key decrypts it. Only the holder of the private key can read the message, making it secure even when the public key is shared openly. This method is used in digital certificates, email encryption, and secure website authentication.
Each method has its strengths. Symmetric encryption is ideal for securing data once the key has already been safely shared. Asymmetric encryption is better for secure exchanges, identity verification, and small data transmissions. Often, the two are used together in what is called hybrid encryption. In this model, asymmetric encryption is used to exchange a temporary symmetric key, which then handles the actual data encryption. This combines speed and security in a single solution.
Key exchange is another important topic. Symmetric encryption requires that both sides obtain the same key securely. This can be done through secure channels or by using asymmetric encryption to transmit the symmetric key. Protocols like Diffie-Hellman allow two parties to generate a shared key over an insecure connection. Elliptic Curve Diffie-Hellman is a modern version that offers strong security with shorter key lengths.
Popular encryption algorithms vary depending on use. For symmetric encryption, Advanced Encryption Standard is the most widely adopted. It is fast, secure, and scalable. For asymmetric encryption, Rivest-Shamir-Adleman is a common choice, along with Elliptic Curve Cryptography. These algorithms are strong enough to resist current brute-force attacks—assuming the key lengths are adequate.
Speaking of key lengths, they are a critical part of encryption strength. A longer key is harder to break. For example, a symmetric key of one twenty-eight bits is considered secure today, but two fifty-six bits provides extra strength. In asymmetric encryption, key sizes typically start at two thousand forty-eight bits or more. Choosing the right key length balances security with performance, and industry best practices evolve over time as computing power increases.
For the Security Plus exam, make sure you can distinguish between types and levels of encryption—like full-disk, file-level, and record-level—as well as transport encryption tools such as Secure Sockets Layer and Internet Protocol Security. Understand when to use symmetric versus asymmetric encryption, and know the basic algorithms and key lengths associated with each. You may also be asked to match encryption methods with scenarios or explain the benefits of hybrid encryption in secure communications.