Cryptographic Enclave: Problems & Common Hardware Enclaves for Better Security

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We are in an era where security and data privacy are paramount. Technological advancement is continuing security experts to push the boundaries of what was possible earlier versus how to make security more sophisticated. Among various security measures, encryption remains a primary technique to prevent information from malicious actors.  

But, with the evolution of technology, some cryptographic techniques are becoming weaker. That gave birth to another innovative rise of cryptographic technique – the cryptographic security enclave. This article will delve into cryptographic enclaves, exploring various problems & attack vectors. We will also probe the solutions that enterprises leverage for the same. 

What is a Cryptographic Enclave?

A Cryptographic Enclave or Secure Enclave is a hardware-level security isolation and memory encryption technique within a computing environment. In this computing environment, sensitive operations such as generating and managing cryptographic keys or other highly prudent actions occur with a high degree of integrity & confidentiality. It can isolate cryptographic codes and data from anyone with privileges. 

Security enclaves are also known as trusted enclaves as they offer high-end confidentiality by relying on hardware-based security mechanisms or Trusted Execution Environments (TEEs). Cryptographic enclaves offer protection against sensitive exposure to the broader system or external adversaries. It acts like a fortified vault that prevents cryptographic key generation and management from hardware, bit-level attacks, and other hardware or software vulnerabilities.

History of Security Enclaves

Cryptographic enclaves came into the limelight in 2013 with the release of iPhone 5S. Back then, when everyone focused on its new camera, high-end camera quality, and features such as Touch ID – Apple introduced its Secure Enclave Processor (SEP) as a revolution for the cryptographic world. To support the iPhone’s Touch ID, Apple underpinned Secure Enclave Processor (SEP) as a separate sub-processor that would store sensitive data & run delicate operations in an isolated & encrypted hardware environment. Later, it gained popularity across other hardware and systems where cryptographic keys needed more hardening.

The Attack Vectors: Various Security Problems Revolving Around Cryptographic Enclaves

Keys used in encryption algorithms are generated and stored using secure enclave techniques that comprise encrypted RAM. However, they remain susceptible to various attacks and threats that attackers use at a hardware level. Let us discuss the different attack vectors cybercriminals use to target cryptographic enclaves.

  1. Memory dump attack: Memory dump, RAM scraping, or memory scraping is an attack technique where the attacker tries to steal sensitive details from the system’s memory (usually the RAM) by compromising it at a hardware level. In such attacks, the cybercriminal exploits various flaws and vulnerabilities in the software running in the memory. Attackers also try to sneak in through hardware vulnerabilities to gain unauthorized access to data stored in the memory during the process. Some attackers misuse forensic tools and techniques to inject malware and extract valuable information from the memory.
  2. Cold boot attack: Users reboot the computer to start or restart it. The cold boot attack is a cyberattack where the adversary tries to steal the data piled in DRAM & SRAM during reboot. The stealing occurs right before the volatile memory erases its content at reboot. Attackers target memory data remanence for sensitive data exposure used in security enclaves. Data remanence is a term that describes the data that remains on a memory module even after the power supply stops. It can be a potential security risk, as an attacker can retrieve sensitive information such as private keys by quickly rebooting a system to an alternative OS and scanning the RAM.
  3. Side channel attack: In this attack technique, the attacker exploits the flaws or vulnerabilities in the physical implementation or hardware used in the cryptographic system. The target is not directly on the cryptographic algorithms but the hardware used to produce the cryptographic keys. The side channel attack leverages unintended information leakage through multiple physical properties such as electromagnetic emissions, power consumption, acoustic emanations, timing variations, etc. Side-channel attacks can be dangerous for security enclaves as they tend to infer sensitive information, such as cryptographic keys, plaintext data, etc.

Well-known Hardware Enclaves used in Cryptographic Functions

Various types of hardware & peripheral devices are utilized as hardware enclaves for cryptographic operations. Some well-known ones are:

  • Hardware security token: These are small USB-based or NFC-type physical devices used for two-factor or multi-factor authentication for security systems. They enable users with digital signatures of digital tokens. Such hardware contains cryptographic keys that work with other security mechanisms and software to provide an additional layer to users’ authentication. They act as a “something you have” element of multi-factor authentication.
  • Trusted Platform Module (TPM): These are specialized hardware or chips mounted on the motherboard to deliver security-related operations. Such hardware comes with multiple uses. They can store passkeys, digital certificates, cryptographic keys, and other security credentials. They operate as hardware authentication modules and ensure systems’ integrity.
  • Smart Cards: Another hardware that enterprises leverage for cryptographic functions is Smart cards. These tamper-resistant portable devices come with embedded integrated circuits holding encryption keys & other security credentials. Enterprises that leverage security enclaves use smart cards for digital authentication and user identification.
  • Hardware Security Module (HSM): These are specialized hardware designed to handle secure key management and cryptographic operations. They have mechanisms to generate, store, and drive cryptographic keys for occasions like digital signing, encrypting or decrypting files, integrity checks, and hashing. Banks and cloud services are well-known sectors that use these hardware security modules.

Apart from all these hardware enclaves, some companies offer proprietary hardware used in cryptographic functions, such as Apple’s Secure Enclave Processor, Intel’s SGX, and ARM’s TrustZone. These companies provide their firmware updates and fix hardware vulnerabilities to prevent modern attacks targeting secure enclaves.

Protecting Hardware from Breaches & Attacks for Cryptographic Enclaves

Since hardware-based attacks & hardware security breaches have become widespread techniques for cybercriminals, enterprises should take proactive measures & robust implementations to prevent security enclaves from cyber threats. Here are some strategies to enhance the protection of hardware-based cryptographic enclaves:

  1. Secure hardware design: Enterprises should take assertive measures such as privilege separation, least privilege, and hardware isolation techniques to create a trusted environment for cryptographic operations. For sensitive cryptographic operations, enterprises can secure the hardware design using Hardware Security Modules (HSMs) to equip isolated & tamper-resistant execution environments.
  2. Countermeasures against side-channel: Security experts can leverage countermeasures to minimize information leakage by enforcing masking, blinding, and randomization techniques. Security professionals can also eliminate side-channeling by employing algorithms that offer built-in resistance, such as constant-time algorithms.
  3. Firmware integrity & secure booting: Another best practice to prevent attacks on secure enclaves is implementing integrity checks on firmware usage and updates. It is because the firmware is system software that gets loaded into the memory when the hardware runs other cryptographic modules. Again, these integrity checks should come as an added support for secure boot mechanisms to establish trust between the bootloader & the operating system.
  4. Secure Key management techniques: Cryptographic keys are the primary component for securing an application, data, network, or any other enterprise asset. Therefore, implementing secure ways of managing the cryptographic keys used in enclaves is essential. Cryptographic key management includes the complete life cycle from cryptographic key generation, storage mechanisms, distribution of public and private keys, and other management done on memory.
  1. Security audits and hardware-level updates: Enterprises should conduct periodic audits and vulnerability assessments for all hardware used in security enclaves. Furthermore, the audits should check whether all the hardware & their associated firmware are up-to-date or depreciated. Through appropriate audits & bug fixing techniques, enterprises can bolster the cryptographic enclave process.

Conclusion

We hope this article curated a crisp idea of cryptographic enclaves and the various attack vectors associated. The article also came forward with some remarkable preventive measures against breaches and possible attacks on cryptographic enclaves. Apart from these measures and techniques, security companies and departments should also provide awareness & training. They should design explicit training for personnel & employees responsible for managing and maintaining hardware-based security enclaves. These employees include developers, security administrators, and system operators. 

In addition to implementing robust preventive measures and providing comprehensive training, security companies and departments can further enhance their defenses by leveraging specialized expertise and resources offered by VE3. Through our innovative solutions and support, you can access cutting-edge technologies, receive tailored guidance, and stay updated on the latest advancements in cryptographic enclave security, bolstering their overall resilience against emerging threats in the digital landscape. To know more, explore our innovative digital solutions or contact us directly.

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