Three layers of digital asset security explored at Paribu Custody webinar

Paribu Custody held its third webinar on March 31, focusing on challenges and solutions in digital asset security. The session examined how ColdShield® addresses structural security problems at a technical level.

The session featured Senior Manager, Product Burcu Atalan and Engineering Manager Ahmet Mesut Şahinoğlu. Atalan explained that ColdShield® was originally developed to secure Paribu users' digital assets without reliance on external providers, guided by the principle of data sovereignty. As the regulatory framework took shape, it evolved into a B2B product under the Paribu Custody brand. She noted that developments such as real-world asset tokenization, staking, and payment infrastructure all require robust custody infrastructure, precisely what ColdShield® is designed to deliver.

Şahinoğlu emphasized that who accesses a system and with what authority is just as important as how keys are stored. He noted that ColdShield® combines MPC, Secure Enclave, and HSM technologies, grounding its security claims in scientific foundations rather than engineering decisions alone.

Admin Quorum eliminates single points of authority

Atalan described the Admin Quorum structure, which eliminates single points of authority. Critical operations, such as defining new permissions or adding secure addresses, require multi-signature approval from the council. Each member holds a device-bound digital certificate that logs all activity, triggering instant alerts on any unauthorized attempt. External risks from components such as price feeds or blockchain nodes are managed through multi-source verification.

Policy engine operates on a default-deny principle

Şahinoğlu explained that ColdShield®'s policy engine operates on a default-deny principle: all transfers are blocked at initialization, and permissions expand only as explicitly defined. Every rule change carries a trace of the previous one, so any tampering breaks the chain and halts the system.

Blind signing risk countered with multi-layer verification

On blind signing, Şahinoğlu noted that many past global security breaches involved no direct key compromise; instead, attackers manipulated third-party components to push HSMs into blind signing.

ColdShield® counters this by hashing all critical parameters at the moment a transaction is created and validating them against the policy engine. Data is transferred to the HSM exclusively via QR code using predefined data structures, with no Wi-Fi or Bluetooth connectivity. Before signing, the HSM verifies the request's origin, the policy rule it passed through, and the source's authorization, making it a context-aware security layer rather than a passive signing device.