foreword
Original link
（1）https://militaryembedded.com/cyber/cybersecurity/designing-and-implementing-secure-boot-for-military-grade-systems
Foreword
Military-grade systems require a high level of security to protect sensitive information and operations from unauthorized access, modification, or disruption.
Military-grade systems require a high level of security to protect sensitive information and operations from unauthorized access, modification or destruction.
One of the critical components for securing such systems is secure boot, which ensures that only trusted firmware and software can be loaded during system startup and accepted when receiving new updates.
One of the key components in securing such systems is Secure Boot, which ensures that only trusted firmware and software are loaded during system startup and are accepted when new updates are received.
Secure boot is a security feature that verifies the authenticity and integrity of firmware and software before loading them into the system memory during the boot process.
Secure Boot is a security feature that verifies the authenticity and integrity of firmware and software before they are loaded into system memory during the boot process.
The mechanism ensures that only trusted firmware and software are executed and mitigates attacks that aim to modify or replace firmware or software with malicious code.
This mechanism ensures that only trusted firmware and software are executed and mitigates attacks aimed at modifying or replacing firmware or software with malicious code.
Secure boot uses digital signatures and cryptographic hashes to verify the authenticity and integrity of firmware and software.
Secure Boot uses digital signatures and cryptographic hashes to verify the authenticity and integrity of firmware and software.
The primary purpose of a secure boot mechanism is to guard against several types of attacks, including rootkits, bootkits, and other malware that target firmware and software.
The main purpose of the secure boot mechanism is to protect against several types of attacks, including rootkits, bootkits, and other malware targeting firmware and software.
These attacks can compromise the system’s security, potentially causing data breaches, denial of service, and other damaging consequences.
These attacks can compromise the security of a system, possibly leading to data breaches, denial of service, and other destructive consequences.
Secure boot ensures that the system starts in a secure state, making it difficult for attackers to compromise the system’s integrity or confidentiality.
Secure Boot ensures that the system starts in a secure state, making it difficult for attackers to compromise the integrity or confidentiality of the system.
Standard recommendations for secure boot (standard recommendations for secure boot)
The IETF SUIT [Internet Engineering Task Force Software Updates for Internet of Things] specification for secure boot has been standardized in RFC9019, and it provides a comprehensive approach to designing secure bootloaders and firmware updates.
The IETF SUIT [Internet Engineering Task Force Software Updates for the Internet of Things] Secure Boot specification, standardized in RFC9019, provides a comprehensive approach to designing secure boot loaders and firmware updates.
The specification defines a format for firmware images that includes metadata, digital signatures, and cryptographic hashes; this metadata includes information about the firmware, device, and manufacturer, as well as the hash (verification) and the cryptographic signature of the software, enabling the system to verify the authenticity and integrity of the firmware.
This specification defines the format of a firmware image, which includes metadata, digital signatures, and cryptographic hashes; this metadata includes information about the firmware, device, and manufacturer, as well as the hash (authentication) and cryptographic Verify the authenticity and integrity of the firmware.
One of the key recommendations from RFC9019 is the use of a secure bootloader that verifies the authenticity and integrity of the firmware image before loading it into memory.
One of the key recommendations of RFC9019 is to use a secure bootloader to verify the authenticity and integrity of the firmware image before loading it into memory.
The secure bootloader checks the digital signature and cryptographic hash of the firmware image, ensuring that it has not been tampered with or modified.
The secure bootloader checks the digital signature and cryptographic hash of the firmware image to ensure it has not been tampered with or modified.
RFC9019 also recommends the use of a trust anchor or a root of trust (RoT) to store the cryptographic material used for secure boot.
RFC9019 also recommends using an anchor of trust or root of trust (RoT) to store cryptographic material for secure boot.
A trust anchor may consist of any software or hardware-based mechanism that ensures that the public key used for the verification of the firmware authenticity cannot be modified by an attacker.
A trust anchor can consist of any software or hardware-based mechanism to ensure that the public key used to verify the authenticity of the firmware cannot be modified by an attacker.
Selecting a root of trust
A RoT is a specific type of trust anchor that provides a secure environment for generating, storing, and managing cryptographic keys.
A RoT is a specific type of trust anchor that provides a secure environment for generating, storing, and managing cryptographic keys.
The RoT ensures that these keys are not compromised or tampered with, and it is typically implemented in hardware to provide a high level of security.
RoT ensures that these keys cannot be compromised or tampered with, and is usually implemented in hardware to provide a high level of security.
The RoT is the foundation of the system’s security, and it is used to establish trust in the system’s firmware, software, and other components.
The RoT is the foundation of system security and is used to establish trust in the system firmware, software, and other components.
In the context of secure boot, a RoT can be implemented using several different technologies, such as hardware security modules (HSM) or trusted platform modules (TPM).
In the context of secure boot, RoT can be implemented using a number of different technologies, such as hardware security modules (HSMs) or trusted platform modules (TPMs).
Executing the cryptographic operations with the assistance of a dedicated hardware component is the most secure option, because it guarantees that the keys are never exposed to the software components, thereby reducing the attack surface for the secure boot module.
Performing cryptographic operations with the assistance of dedicated hardware components is the most secure option because it guarantees that the keys are never exposed to software components, thereby reducing the attack surface of the secure boot module.
Compatibility with the embedded system is an important consideration when selecting a trust anchor or RoT. The RoT must be compatible with the hardware and firmware of the system, ensuring that it can be integrated seamlessly into the boot process.
Compatibility with embedded systems is an important consideration when choosing a trust anchor or RoT. The RoT must be compatible with the system's hardware and firmware, ensuring it can be seamlessly integrated into the boot process.
The RoT should also support the required cryptographic algorithms and protocols, ensuring that it can provide a high level of security for the system. Hardware-based solutions can be more expensive than the software-based counterparts.
The RoT should also support the required encryption algorithms and protocols, ensuring that it can provide a high level of security for the system. Hardware-based solutions can be more expensive than software-based solutions.
While for less critical systems a software-based solution may be sufficient and more cost-effective, the cost of implementing a hardware-based solution is justified for military-grade systems that require a higher level of security.
While a software-based solution may be sufficient and more cost-effective for less critical systems, for military-grade systems that require higher levels of security, the cost of implementing a hardware-based solution is justified.
Retrofitting older systems
Retrofitting older systems with secure boot can be difficult and expensive, as it may require both hardware and software upgrades. The cost and feasibility depend on several factors.
Retrofitting legacy systems with Secure Boot can be difficult and expensive, as it may require hardware and software upgrades. Cost and feasibility depend on several factors.
One of the main challenges of retrofitting older systems with secure boot is that many legacy systems were not designed with security in mind.
One of the main challenges of retrofitting legacy systems with secure boot is that many legacy systems were not designed with security in mind.
This means that the system architecture may not support the necessary security features required for secure boot, such as a FIPS-compliant (a longstanding data-security standard) cryptographic module, or hardware-based RoT or HSM.
This means that the system architecture may not support the necessary security features required for secure boot, such as FIPS (Long-standing Data Security Standard) compliant cryptographic modules or hardware-based RoTs or HSMs.
In some cases it may be necessary to redesign the system boot process to include secure boot stages, which can be a time-consuming and expensive process.
In some cases, it may be necessary to redesign the system boot process to include a secure boot phase, which can be a time-consuming and expensive process.
Another obstacle found in retrofitting older systems with secure boot is the availability of existing bootloaders. Many legacy systems use custom bootloaders that do not support secure boot; in these cases, it may be necessary to modify the bootloader(s) to support secure boot.
Another hurdle found when retrofitting legacy systems with Secure Boot is the availability of existing bootloaders. Many older systems use custom bootloaders that do not support Secure Boot; in these cases, it may be necessary to modify the bootloader to support Secure Boot.
The bootloader must be able to communicate with the trust anchor or RoT and perform the necessary integrity and authenticity verifications during the boot process.
The bootloader must be able to communicate with the trust anchor or RoT and perform the necessary integrity and authenticity verification during the boot process.
Integrating cryptographic modules to provide the required integrity and authenticity verifications at startup is also an option to consider when retrofitting older systems. The system must be able to store and manage cryptographic keys securely, ensuring that they are not compromised or tampered with.
Integrating cryptographic modules to provide the required integrity and authenticity verification at boot time is also an option to consider when retrofitting legacy systems. The system must be able to securely store and manage encryption keys so that they cannot be compromised or tampered with.
In addition, the cryptographic modules must be able to perform the necessary cryptographic operations efficiently to minimize the impact on system performance, which – in the case of secure boot – is likely to affect startup times.
Additionally, the cryptographic module must be able to efficiently perform the necessary cryptographic operations to minimize the impact on system performance, which in the case of secure boot can impact boot time.
Despite these challenges, retrofitting older systems with secure boot is often necessary to ensure the security of critical systems. In many cases, the cost and feasibility of retrofitting a system with secure boot can be reduced by using existing software-based solutions, such as secure boot software that can be installed on existing hardware or integrated in existing legacy bootloaders.
Despite these challenges, a secure boot retrofit of legacy systems is often necessary to keep critical systems secure. In many cases, the cost and feasibility of retrofitting a system with Secure Boot can be reduced by using existing software-based solutions such as Secure Boot software that can be installed on existing hardware or integrated into existing legacy boot loaders sex.
However, for military-grade systems or systems that require a higher level of security, a hardware-based solution is often necessary, which can increase the cost and complexity of the retrofitting process. (Figure 1.)
However, for military-grade systems or systems that require higher levels of security, hardware-based solutions are often required, adding cost and complexity to the retrofit process. (figure 1.)
[Figure 1 ǀ A data wall provides real-time worldwide information for the 175th Cyberspace Operations Group of the Maryland Air National Guard. U.S. Air Force photo by J.M. Eddins Jr.]
[Figure 1 ǀ The Data Wall provides real-time global information to the 175th Cyberspace Operations Group of the Maryland Air National Guard. U.S. Air Force Photo: JM Eddins Jr.]
FIPS cryptography as a necessity for military-grade systems (FIPS encryption is a necessity for military-grade systems)
Among its recommendations, RFC9019 stresses the use of FIPS-compliant cryptography for the algorithm used by secure boot. This is particularly important for military-grade systems. FIPS – the acronym used for Federal Information Processing Standard – is a set of standards developed by the National Institute of Standards and Technology (NIST) expressly to ensure the security of sensitive government information.
Among its recommendations, RFC9019 emphasizes that the algorithms used by Secure Boot should use FIPS-compliant cryptography. This is especially important for military-grade systems. FIPS (short for Federal Information Processing Standards) is a set of standards developed by the National Institute of Standards and Technology (NIST) to ensure the security of sensitive government information.
FIPS-compliant cryptography is designed to be strong and secure, and it has been rigorously tested and validated to ensure that it meets the highest security standards.
FIPS-compliant encryption technology is designed to be strong and secure, and has been rigorously tested and validated to ensure it meets the highest security standards.
While FIPS 140-2 is currently the most widely recognized standard for cryptography, NIST has recently developed a new standard, FIPS 140-3, which updates and will eventually replace FIPS 140-2, introducing new requirements for the validation of cryptographic algorithms and modules.
While FIPS 140-2 is currently the most widely recognized encryption standard, NIST recently developed a new standard, FIPS 140-3, which updates and eventually replaces FIPS 140-2, introducing new requirements for cryptographic algorithm and module validation.
FIPS 140-2 and FIPS 140-3 provide frameworks for the validation of cryptographic modules, which are sets of hardware, software, and/or firmware that implements cryptographic functions, such as encryption and decryption.
FIPS 140-2 and FIPS 140-3 provide a framework for validating cryptographic modules, which are sets of hardware, software, and/or firmware that implement cryptographic functions such as encryption and decryption.
The widely adopted FIPS 140-2 standard defines the requirements for the design and testing of cryptographic modules, specifying four levels of security based on the level of protection required for the information being secured.
The widely adopted FIPS 140-2 standard defines requirements for the design and testing of cryptographic modules, specifying four security levels based on the level of protection required to protect information.
It’s a rigorous process that involves extensive testing of the cryptographic module to ensure that it meets the security requirements specified in the standard.
This is a rigorous process that involves extensive testing of cryptographic modules to ensure they meet the security requirements specified in the standard.
The process includes testing of the cryptographic algorithms used by the module, as well as testing of the physical and logical security mechanisms used to protect the module from tampering or attack.
The process includes testing the encryption algorithms used by the module, as well as testing the physical and logical security mechanisms used to protect the module from tampering or attack.
For military-grade systems, the use of FIPS-compliant cryptography is essential to ensure the security of sensitive information and critical software components.
For military-grade systems, the use of FIPS-compliant cryptography is critical to securing sensitive information and critical software components.
Military systems are typically targeted by sophisticated attackers, and the use of strong cryptography is necessary to protect against attacks that could compromise the integrity, confidentiality, or availability of the system.
Military systems are often the target of sophisticated attackers, so strong encryption must be used to prevent attacks that could compromise system integrity, confidentiality, or availability.
In a broader scope, the use of FIPS-grade cryptography can also help to ensure interoperability and compatibility with other systems and components that use standard algorithms to ensure the security of sensitive information and critical systems. The importance of FIPS-certified implementations extends as well in the secure boot domain, due to its critical role in the general security of the entire system that can be mitigated by the adoption of the best-in-class cryptographic countermeasures, recommended by the standards.
On a broader scale, the use of FIPS-level encryption also helps ensure interoperability and compatibility with other systems and components that use standard algorithms to keep sensitive information and critical systems safe. The importance of FIPS-certified implementation also extends to the area of secure boot, as it plays a key role in the overall security of the entire system, which can be mitigated by employing standard-recommended best-in-class cryptographic countermeasures.
Daniele Lacamera is a free and open source software technologist, currently based in Italy. His main areas of expertise are embedded systems and TCP/IP communication.
Daniele Lacamera is a free and open source software technologist currently living in Italy. His main areas of expertise are embedded systems and TCP/IP communications.
He has 20-plus academic publications in the field of transport-layer optimization and is the author of the book “Embedded Systems Architecture.” Daniele joined wolfSSL as embedded software engineer in 2018, contributing to the development and the integration of wolfSSL on embedded operating systems and custom transport mechanisms. He is the main contributor to wolfBoot, the universal secure bootloader for embedded systems.
He has more than 20 academic publications in the field of transport layer optimization and is the author of the book Embedded Systems Architecture. Daniele joined WolfSSL in 2018 as an embedded software engineer, working on the development and integration of WolfSSL on embedded operating systems and custom transports. He is a major contributor to WolfBoot, a universal secure bootloader for embedded systems.