White Paper Building a foundation of trust for an expanding PKI ecosystem architecture Critical considerations when protecting the new corporate network, mobility, cloud applications, and the Internet of Things Contents Introduction 3 Why is your PKI more important than ever? 4 The CA and the changing security ecosystem 6 Externally vs. internally hosted CAs 7 Security considerations 10 Ownership within your organization 11 Assessing your PKI dependence 14 Why should you be concerned over the strength of your PKI? 14 Factors to consider when determining your requirements 16 A stronger PKI for the next generation 17 System level CA requirements for a higher-assurance PKI 18 Cryptographic level best practices for a higher-assurance PKI 20 Conclusion 23 2 Introduction Business applications today are increasingly more and more dependent on electronic dependent on the use of trusted digital interaction requiring online authentication credentials. Credentials are the certificates and compliance with stricter data security and keys that controls how users, entities, regulations, next generation business and a growing number of devices connect applications are becoming more reliant on to systems and access critical resources PKI technology to guarantee high assurance. and data. The Public key infrastructure As the core component of a PKI (PKI) is the set of hardware, software, responsible for establishing a hierarchical policies, processes, and procedures chain of trust, certificate authorities (CAs) required to create, manage, distribute, issue the digital credentials used to certify use, store, and revoke digital certificates the identity of users. CAs underpin the and public-keys. As the foundation that security of a PKI and the services they enables the use of technologies such as support, and therefore can be the focus of digital signatures and encryption across sophisticated targeted attacks. Casualties large user populations, PKIs deliver the of these attacks have included CAs such as essential elements necessary for a secure DigiNotar which were put out of business business environment and the trusted after compromised and attacks where ecosystem essential for e-commerce unauthorized certificate issued by an and the growing Internet of Things (IoT). intermediate CA, was used to create bogus According to a recent study, IoT is the most end-entity certificates that ultimately important trend driving the deployment affected numerous Internet websites.2 In of applications using PKI, increasing order to mitigate the risk of attacks against significantly from 21% of respondents CAs, physical and logical controls as well in 2015 to 47% in 2020.1 With a growing as hardening mechanisms have become demand for trusted digital certificates, PKIs necessary to ensure the integrity of a PKI. must meet that challenge. This paper examines the security risks of PKIs help establish the identity of people, typical enterprise and government PKIs. devices, and services – enabling controlled The paper describes how, as more high- access to systems and resources, protection value business applications and growing of data, and accountability in transactions. number of devices increasingly depend on With evolving business models becoming trusted digital credentials, higher assurance 1. 2020 Global PKI and IoT Trends Study, Ponemon Institute. 2. Google Chrome will banish Chinese certificate authority for breach of trust, Arstechnica, 2015. http://arstechnica.com/security/2015/04/google-chrome-will- banish -chinese-certificate-authority-for-breach-of-trust/ LEARN MORE AT ENTRUST.COM/HSM 3 solutions are now necessary to reinforce critical for organizations architecting security and mitigate growing risks. PKIs to implement strong encryption and Analyzing such aspects as the number of digital signatures. Options that should be certificates being used by individuals and considered include using robust algorithms devices, the importance and value of the and longer key lengths, or newer approved applications they support, and whether technologies such as elliptic curve these applications are subject to higher cryptography (ECC) for mobile devices levels of scrutiny due to government with computational limitations. With these, or industry regulatory compliance, are organizations should step back and look at some of the critical factors to consider in their entire infrastructure to determine the assessing whether a PKI can still meet the appropriate assurance level for their PKI demands of an evolving ecosystem. With based on the critical systems they support the backdrop of well-known attacks on today and those that they will support in sensitive data, it has become increasingly the future. Why is your PKI more important than ever? PKIs provide a framework that enables code signing, and time stamping. PKIs cryptographic data security technologies support solutions for desktop login, such as digital certificates and signatures citizen identification, mass transit, mobile to be effectively deployed on a mass banking, and are critically important for scale. As a foundational element of many device credentialing in the IoT. Device trusted systems, PKIs are already present credentialing is becoming increasingly in more places than one would generally important to impart identities think. PKIs support identity management to growing numbers of cloud-based and services within and across networks, and internet-connected devices that run the underpin online authentication inherent in gamut from smart phones to medical secure socket layer (SSL) and transport equipment. In the next two years, an layer security (TLS) for protecting average of 41% of IoT devices in use will internet traffic, as well as document rely primarily on digital certificates for and transaction signing, application identification and authentication.3 3. Ibid. 4 Software and firmware that runs on IoT in a transaction. Much like a passport devices also need digital certificates certifies one’s identity as a citizen of a to affirm its integrity and protect from country, the digital certificate establishes malware. With an estimate of 20 billion the identity of users within the ecosystem. IoT devices now deployed, the number of Because digital certificates are used to digital certificates is expected to explode identify the users to whom encrypted data in the coming years, and demand for PKIs is sent, or to verify the identity of the signer to grow rapidly. of information, protecting the authenticity and integrity of the certificate is imperative Using the principles of asymmetric and in order to maintain the trustworthiness symmetric cryptography, PKIs facilitate of the system. the establishment of a secure exchange of data between users and devices – With evolving business models becoming ensuring authenticity, confidentiality, more and more dependent on electronic and integrity of transactions. Users (also transactions and digital documents, known as “Subscribers” in PKI parlance) and with more Internet-aware devices can be individual end users, web servers, connected to corporate networks, the role embedded systems, connected devices, or of a PKI is no longer limited to isolated programs/applications that are executing systems such as secure email, smart cards business processes – for simplicity in for physical access or encrypted web this paper we refer to these generically traffic. PKIs today are expected to support as “users”. Asymmetric cryptography larger number of applications, users and provides the users, devices or services devices across complex ecosystems. And within an ecosystem with a key pair with stricter government and industry data composed of a public and a private key security regulations, mainstream operating component. A public key is available to systems and business applications are anyone in the group for encryption or becoming more reliant than ever on an for verification of a digital signature. The organizational PKI to guarantee trust. private key on the other hand, must be kept secret and is only used by the entity PKIs today are expected to to which it belongs, typically for tasks support larger number of such as decryption or for the creation of applications, users and devices digital signatures. across complex ecosystems – a task that they were not originally In order to bind public keys with their designed to do. associated user (owner of the private key), PKIs use digital certificates. Digital certificates are the credentials that facilitate the verification of identities between users LEARN MORE AT ENTRUST.COM/HSM 5 The CA and the changing security ecosystem CAs manage the lifecycle of all digital of certificates. Managed/hosted services credentials within a PKI, including their can be accessed by multiple private issuance, renewal, and revocation. The organizations with “Commercial CAs” digital credential, often referred to as an also being accessible to the general X.509 certificate4, validates the ownership public. Both managed/hosted CA services of a public key by the named subject of and “Commercial CAs” therefore serve the certificate. When receiving digitally the purpose of establishing trust between signed information, the certificate enables all the parties in a transaction making users (signers (“Subscribers”) and use of certificates, effectively acting as a verifiers (“Relying Parties”)) to validate trusted third party. that the private key used to create the Applications most often using PKI signature indeed belongs to the person or credentials