# A Public Infrastructure for a Trusted Wireless World
## 5 A Roadmap for Updating Existing Frameworks to Obtain Trusted Digital Identities  
In order to manage the vast number of devices, in addition to making people feel confident that a machine such as an e-voting system or a person is who they say they are, companies must deploy digital-credentialing systems and methods. Since trust is more of a social construct, giving it meaning and finding measurements within an electronic system proves challenging. The existing self-sovereign identities of the internet must be changed. Public key infrastructure (PKI) has been around for decades as a means of identifying and authenticating individuals and machines. A PKI will provide the policies, roles, software, hardware, and procedures necessary to create, manage, distribute, use, store, and revoke digital certificates. The most important aspect of PKI is that it establishes the identities of people, devices, and services [14]. However, PKI is outdated and in need of a facelift. Blockchain provides a mechanism to update PKI in order to meet the demands of a mobile 21 st century. The PKI framework, as it currently exists, has vulnerabilities. Reporting unauthorized certificates is a time-consuming and labor-intensive effort that leaves a CA open to a man-in-the-middle (MITM) attack. If the CAs are not operating correctly, the introduction of encryption has no value. Blockchain-based PKI techniques provide methods to secure the CA vulnerabilities immediately in real time [27]. In order to affectively implement blockchain within PKI, establishing trust would be necessary to instantiate security measures against interference, breach, and eavesdropping [28]. A considerable vulnerability to PKI applications and platforms is their dependence on a centralized cloud. PKI, in its current form, is centralized, relying on trusted third parties. Decentralizing and incorporating blockchains provides the means of overcoming several of the problems linked with the centralized cloud approach. Provenance and other startups are using blockchain to promote trust in product transactions from the source to the customer [29]. Blockchains can cryptographically sign transactions and verify the originator's cryptographic signature to guarantee a message's origin [29]. Blockchains also provide secure traceability of certifications and other relevant data in supply chains. Blockchain's public availability ensures transactions can be linked to identify vulnerable mobile devices [28]. Suitable for registering time, location, price, parties, and data, as they move through the supply chain, blockchain-based PKI systems will help strengthen mobile device security [29]. A blockchain-based PKI running on a 5G network will allow for significantly improved performance and capabilities within mobile devices. Blockchain-based PKI's authentication service will improve because 5G will employ higher and more directional frequencies such that the data signals can transmit more precisely using less energy [16]. In addition, blockchain-based PKI alloys several deficiencies of the existing CA within PKI, the primary deficiency being the centralization of the CA [30]. Following the Identity, Credential, and Access Management (ICAM) framework laid out in Trusted Digital Identities for Mobile Devices, the CA can be made distributed [20]. A distributed system is where all of the parties work together as a single coherent system. It has qualities of centralization and decentralization. There is still a central authority that has some control over the other parties in governing processes, yet the other parties can make many of their own decisions and work autonomously. Distribution improves availability, reliability, fault tolerance, performance, and scalability [7]. Blockchain-based PKI utilizing NFC, as proposed in the ICAM framework [20], allows PKI to solve the challenges faced with online voting and BYOD. The ICAM system provides the authentication/authorization piece to the blockchain-based PKI e-voting system (BPES).