Authentication Policy Rule Evaluation — Conditional Short-Circuit Behavior

Products

• Symantec Identity Security Platform - IDSP (formerly VIP Authentication Hub)

Issue/Introduction

When configuring authentication policies in IDSP, administrators can define multiple **rules** within a single policy, and multiple **conditions** within each rule (e.g., a context/company identifier check alongside a large list of IP ranges). A common question arises:

When the policy engine processes the conditions on an authentication rule, does it short-circuit on failure — specifically, if an early condition (such as a quick string comparison on a context field) fails, does the engine skip the remaining expensive conditions (such as iterating through a large IP range list) and move to the next rule?

Environment

Symantec Identity Security Platform (IDSP) 4.0

Resolution

The IDSP policy engine (powered by OPA) utilizes short-circuit evaluation at both the rule level and the condition level.

Consolidating all IP restriction rules into a single policy—where each rule uses a context conditional to identify the target company before evaluating IP ranges—is a supported and highly efficient design.

Evaluation Mechanics

• Condition-Level Short-Circuit: If a context or company identifier check fails, the engine immediately skips the remaining conditions within that rule (including the IP range evaluation) and proceeds to the next rule.

• Rule-Level Short-Circuit: Once a rule criteria is met or failed, the engine deterministically moves through the hierarchy based on defined priorities.

Short-Circuit Scenarios

Scenario	Short-Circuit?	Technical Behavior
Company identifier check fails	Yes	OPA short-circuits immediately when a condition fails within a rule body, skipping subsequent IP ranges on that rule.
Rule does not match	Yes	The engine skips to the next rule, guaranteed via rulePriority first-match semantics.
Policy does not match	Yes	The engine skips to the next policy, guaranteed via POLICY_PRIORITY ordering.

Best Practice

Always assign sequential values (e.g., 1, 2, 3...) to ensure a deterministic rule processing order. Do not rely on implicit ordering.