What is Secure Boot?

Last Updated : 29 Mar, 2024

Attackers can hack our systems in many ways, like PCs, laptops, desktops, etc. They take control of our system due to malpractice. Booting is also a technique through which an attacker executes malicious software and enters the system. In this article includes we will see all secure boot in detail.

What is Secure Boot?

Secure boot is a security standard that ensures that only trusted software executed on the system has been approved by the PC manufacturers. PC manufacturers make it to secure the system from malicious software execution. It supports modern Windows, Linux, etc. When secure boot is enabled from the firmware the system matches the signature of executable files before allowing the file to execute.

It safeguards our system against the execution of malicious and unauthorized codes. When we start the PC, the firmware checks the signature of each boot software, if the signatures are matched, then the system boots and control is given to the operating system from the firmware. Secure boot doesn’t need TPM and it also doesn’t encrypt the storage of the system.

Example:- When we first power on the modern PC with UEFI firmware secure boot comes into action before allocating resources to the memory. It supports Windows, Linux, and macOS.

Why is Secure Boot important?

A secure boot is not the best security solution but it can make our system more secure by eliminating the execution of malicious data on our system. It ensures that only authenticated and unaltered components are loaded during the boot process to maintain the integrity of the system.
It prevents unauthorized modification to the boot process.
Secure boot adds a security layer to remote or cloud-based management.
The secure boot provides security features that protect our system from unauthorized access, tempering attempts, and malware inclusion.

Disadvantages of Secure Boot

Restricts users from installing alternative operating systems which may be important for users.
It also blocks the important software if its signature is not matched or invalid.
It can be exploited through vulnerabilities in the firmware, hardware, etc.
It increases the complexity of the boot process.

Secure Boot Requirements

UEFI Firmware: To implement secure boot, the system must support Unified Extensible Firmware and interface firmware.
Cryptographic Keys: Secure boot depends on the digital signatures generated using cryptographic keys.
Certificate Authority: Certificate authority issues the digital certificate that is used for signing boot components.
Signature Verification: During the boot process firmware verifies the digital signature of each component against the embedded public Key.
Secure boot configuration: The system provides the setting of enabling or disabling secure boot.
Vendor & Hardware Provider: A hardware Provider manufacturing company plays a vital role in manufacturing the hardware system that supports secure boot. They also provide secure boot keys.

How Does Secure Boot Work?

As shown in the diagram below “Firmware initialization” is the first process when the system is powered on. Now “Secure Boot verification” verifies the digital signatures of each boot component against the public keys of the embedded system which is provided by the vendors while manufacturing. If the keys are valid then it moves to the next step i.e. embedded public keys and if it is not valid it again goes to the firmware initialization. The embedded public keys are provided by the vendor or hardware manufacturer and all the sets of keys are stored in the firmware. When one component’s signature is valid it adds the next component in the chain for verification. When all the boot components are verified and valid the firmware loads the operating system kernel into memory. In the secure boot policy, endorsement-enabled and disabled options are included. Protected against malware protects our system from malicious or unauthorized software whose signature is missing or invalid.

Working on Secure Boot

Conclusion

Secure boot doesn’t provide the proper protection against attackers but it increases difficulty for the attackers to enter into the system. It secures our system from unauthorized access and malicious software. While booting, the system firmware verifies the booting components with the key provided by the manufacturer in the firmware if valid then only it does the further process of booting.

Frequently Asked Questions on Secure Boot – FAQs