What Is PKOC? How Will It Make Access Control Solutions More Interoperable?

PKOC stands for Public Key Open Credential. It is a new standard that will meet a 30-year industry challenge and strip away much of the complexity and cost involved in protecting and administering credentials for access control. It could also accelerate the transition from cards to mobile access control.

PKOC is a standards-based mobile credential that is essentially free, vendor-agnostic, and interoperable across multiple devices and systems. It is a highly secure access credential that can live on a mobile phone, in a plastic access card, or in any device capable of generating a public-private key pair.

Access control systems

PKOC is the newest standard of the Physical Security Interoperability Alliance (PSIA), a tax-exempt organization created to define, recommend, and promote standards for IP-enabled security devices and systems.

PSIA introduced the Physical Logical Access Interoperability (PLAI) specification in 2013 to normalize identity data across disparate physical access control systems. The PKOC specification was introduced in 2021.

We’re convinced this is the future

A challenge for PSIA in promoting the PKOC mobile credential is to explain it quickly and in layman’s terms

“We see the benefit of implementing the PKOC technology and doing it well,” says Sam Siegel, Senior Field Applications Engineer for ELATEC, a manufacturer of credential-agnostic readers/writers. “We wanted to get involved and join the discussion.” ELATEC has been participating in PSIA for more than a year. “This is a better way to do things,” says Siegel.

“The PSIA, myself included, are convinced this is the future. The challenge is to get enough people to understand that it is a seismic shift away from what has been in place for so long.” A challenge for PSIA in promoting the PKOC mobile credential is to explain it quickly and in layman’s terms. The explanation spans the concept of public key infrastructure (PKI) and the difference between symmetrical and asymmetrical digital keys.

Protecting symmetrical keys

A symmetrical key system, which has been used historically in the access control market, involves the use of a single proprietary digital key to both encrypt and decrypt information. This means that digital public keys must be incorporated into each access control reader in the form of a module or a license, which the reader uses to read any compatible cards.

Protecting symmetrical keys has been an expensive technology challenge the access control world

The need to share these digital keys (in effect, the ability to read every compatible card) securely among access control manufacturers, integrators and end users involves extra administration and costs to ensure the security of the system. Protecting symmetrical keys has been an expensive technology challenge the access control world has borne for decades. The use of proprietary keys also promotes dependence on a single manufacturer or vendor to expand the ecosystem. The use of asymmetrical keys takes away these challenges.

Advantages of using asymmetrical key pairs

PKOC embraces the principle of PKI (public key infrastructure), a two-key asymmetrical system used to ensure confidentiality and encryption. In effect, there are two digital "keys," one public and one private, that are used to encrypt and decrypt information, in this case, a credential for an access control system. The secure credential standard is generated independently of a third-party credential issuer. It is generated within the device.

In the access control scenario, the smartphone generates a key pair in the secure element of the phone, including a private key, which is stored on the smartphone, and a public key, which serves as the user’s ID number in the access control system. Sharing the public key is not a security risk because it is worthless without the private key that is locked away on the smartphone.

PKOC-enabled smartphone

The smartphone must contain the private key in order to interface with the access control system

When a PKOC-enabled smartphone approaches a PKOC-enabled reader, the reader sends a one-time random number (a ‘nonce’) to the smartphone, which then encrypts it using the private key, and sends it along with the public key back to the reader. The reader uses the public key to decrypt the random number, which confirms the authorized access associated with the smartphone. The signals are sent via Bluetooth Low Energy (BLE). 

Importantly, the private key never leaves the smartphone and is never shared with any other elements of the access control system. Therefore, there are no administrative or technical costs associated with protecting it. The smartphone must contain the private key in order to interface with the access control system using the public key.

Mobile credentialing system

For ELATEC, embracing PKOC provides a new way to highlight the company’s value proposition and promote it to a new group of companies; i.e., those who adopt the PKOC approach to mobile credentialing.

The ‘universal’ configuration of the ELATEC reader hardware is credential-agnostic

“PKOC serves as a great way to show off our value and what we do best,” says Siegel. ELATEC provides credential readers/writers that operate in a variety of card and reader environments, incorporating an integrated BLE module to support mobile ID and authentication solutions, including PKOC. Using applicable firmware, the ‘universal’ configuration of the ELATEC reader hardware is credential-agnostic and so compatible with any RFID card or mobile credentialing system, all in a small form factor (around 1 1/2 inches square).

How readers and smartphones interact

The PKOC standard addresses the variables of how the reader and the smartphone share information. Currently, the PKOC standard addresses communication via BLE, but the principle is the same for systems using near-field communication (NFC), ultra-wideband (UWB), or any future protocols. PKOC also defines how device manufacturers can enable devices (readers, locks, control panels, biometric devices, etc.) to securely consume the credential for authentication and access.

PKOC can be used with smart cards as well as with smartphones. In the case of a smart card, the public and private keys are contained on the smart card, which communicates via NFC with the reader. The encryption/decryption scenario is exactly the same. PKOC enables users to ‘bring your own credential’ (BYOC).

Public key number

ELATEC is proud to have played an instrumental role with the PSIA in the implementation of PKOC"

BLE offers a broader read range than NFC; the read range can be managed using software and/or by signaling intent or two-factor authentication. Because private keys remain secure inside a smartphone, they do not have to be incorporated into a digital wallet for security purposes, although they could be incorporated for matters of convenience. 

To simplify administration, the public key number can be used as a badge number. If badge numbers have already been assigned, a column could be added to the database to associate badge numbers with public key numbers.

“ELATEC is proud to have played an instrumental role with the PSIA in the implementation of PKOC,” said Paul Massey, CEO of ELATEC, Inc. “End-users should not be limited in their solution mix to one or two vendors due to their proprietary technology. PKOC now provides the ideal combination of security, convenience, interoperability, and cost for industry participants, by industry participants.”

‘Experience PSIA’ will promote PKOC at ISC West

ISC West participants include PSIM manufacturer Advancis Software and Services

The flexibility of PKOC will be on display at ISC West 2023, where ‘Experience PSIA’ will register attendees and provide them with a PKOC credential that can be used with a variety of readers throughout the show. Also showcasing the PLAI standard, PSIA’s presence at ISC West will include ELATEC along with several other vendors/manufacturers. A special PSIA event will be held from 5:30 to 7:30 p.m. on March 29 at the Venetian Ball Room B&C in Las Vegas.

ISC West participants include PSIM manufacturer Advancis Software and Services, which acquired Cruatech software in 2012; and Idemia, specializing in identity-related security services including facial recognition and other biometrics.

Integrated security systems

Also involved are Johnson Controls (JCI), an integrated security systems provider that offers a range of security products and services; and Siemens, which offers its own range of security solutions and systems.

Other participants include Last Lock, which has a unique spin on internet-enabled locks; while SAFR from Real Networks offers accurate, fast, unbiased face recognition and additional computer vision features, and Sentry Enterprises provides the SentryCard biometric platform for a privacy-centric, proof-of-identity solution. Finally, rfIDEAS manufactures credential readers.