Do you know the different hardware-based encryption devices that ensures data security? You should if you plan to take the Security+ exam. This post should help.
Here’s a sample practice test question:
Q. You are comparing different encryption methods. Which method includes a storage root key?
A. HSM
B. NTFS
C. VSAN
D. TPM
Can you answer the question? More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Hardware-Based Encryption
Although software-based encryption is useful, the drawback is that it can take extra processing power and time. It isn’t as useful when a large quantity of data, such as an entire disk, needs to be encrypted or when performance is a concern.
You can use hardware-based encryption devices, such as a Trusted Platform Module or a hardware security module, for better performance. A significant benefit of hardware encryption is that it is much quicker than software encryption.
The following Table provides an overview of these hardware encryption devices, and the following sections explore them in greater depth. Both use strong asymmetric encryption and provide a secure method of storing encryption keys.
A comparison of TPM and HSM features
Trusted Platform Module
A Trusted Platform Module (TPM) is a hardware chip on the computer’s motherboard that stores cryptographic keys used for encryption. Many laptop computers include a TPM, but if the system doesn’t include a TPM, it is not feasible to add one. Once enabled, the TPM provides full disk encryption capabilities. It keeps hard drives locked, or sealed, until the system completes a system verification and authentication process.
The TPM ships with a unique Rivest, Shamir, Adleman (RSA) key burned into it, which is used for asymmetric encryption. Additionally, the TPM can generate, store, and protect other keys used for encrypting and decrypting disks. TPMs use three categories of encryption keys:
- Endorsement key. The manufacturer embeds an endorsement key into the TPM. This stays with the TPM throughout its lifetime.
- Storage root key. The TPM creates the storage root key when a user adds a TPM owner password and activates the TPM. The TPM uses this key to create and protect other encryption keys used within applications.
- Application keys. These keys are derived from the storage root key and applications use them to encrypt disks. For example, Microsoft BitLocker uses an application key to encrypt entire disks.
If the system includes a TPM, you use an application within the operating system to enable it. For example, many Microsoft systems include BitLocker, which you can enable for systems that include the TPM.
BitLocker uses the TPM to detect tampering of any critical operating system files or processes as part of a platform verification process. Additionally, users provide authentication, such as with a smart card, a password, or a personal identification number (PIN). The drive remains locked until the platform verification and user authentication processes are complete.
If a thief steals the system, the drive remains locked and protected. An attacker wouldn’t have authentication credentials, so he can’t access the drive using a normal boot-up process. If the attacker tries to modify the operating system to bypass security controls, the TPM detects the tampering and keeps the drive locked. If a thief moves the drive to another system, the drive remains locked because the TPM isn’t available.
Remember this
A Trusted Platform Module (TPM) is a hardware chip on the motherboard included on many newer laptops and it provides full disk encryption. A TPM includes a unique RSA asymmetric key. When a user activates the TPM, it creates a storage root key, which the TPM uses to generate and store other cryptographic keys.
Hardware Security Module
A hardware security module (HSM) is a security device you can add to a system to manage, generate, and securely store cryptographic keys. High-performance HSMs are external devices connected to a network using TCP/IP. Smaller HSMs come as expansion cards you install within a server, or as devices you plug into computer ports.
One of the noteworthy differences between an HSM and a TPM is that HSMs are removable or external devices. In comparison, a TPM is a chip embedded into the motherboard. You can easily add an HSM to a system or a network, but if a system didn’t ship with a TPM, it’s not feasible to add one later. Both HSMs and TPMs provide secure encryption capabilities by storing and using RSA keys. Many high-performance servers use HSMs to store and protect keys.
Remember this
A hardware security module (HSM) is a removable or external device that can generate, store, and manage RSA keys used in asymmetric encryption. Many server-based applications use an HSM to protect keys.
Q. You are comparing different encryption methods. Which method includes a storage root key?
A. HSM
B. NTFS
C. VSAN
D. TPM
Answer is D. A Trusted Platform Module (TPM) includes a storage root key. The TPM generates this key when a user activates the TPM.
A hardware security module (HSM) uses RSA keys, but not a storage root key.
NT File System (NTFS) supports encryption with Encrypting File System (EFS).
A virtual storage area network (VSAN) is a virtualization technique, and it doesn’t provide encryption.