How Does Proof-of-Work Contribute to the Security of Proof-of-Activity?

Proof-of-Work (PoW) in PoA ensures the initial block creation process is computationally intensive and costly. This difficulty makes it expensive for an attacker to rapidly produce fake block headers.

It establishes a verifiable, energy-backed history for the block chain. The 'work' done acts as a deterrent against spamming the network with empty or malicious blocks.

This initial step anchors the security before the staking phase begins.