Industrial Internet of Things (IIoT) is a network of things that are connected to form a system to monitor, communicate, and analyze data with collective intelligence. Internet of Things (IoT) has been a driving technology for many of the sectors. Industrial automated systems is one such sector that has been deeply influenced. Ensuring the security of IIoT devices presents significant challenges, particularly in critical infrastructure. The current work advances Security-by-Design (SbD) paradigm in IIoT. This paper proposes a novel blockchain-based verified patch delivery system that also integrates Verifiable Delay Functions (VDFs) to provide a two-layer security. Blockchain provides a tamper-proof ledger for verifying the integrity of patches as well as identification of IIoT devices preventing rogue devices in the network. VDFs introduced help create a synchronized patching across the critical infrastructure devices which avoids patch exploitation by adversaries by reducing the attack surface.