Allowlist/Denylist Services: Fluid and Not-fluid Data

Alloy recognizes that not all Personally Identifiable Information (PII) should be matched in the same way. PII like a first name can be variable e.g. Sam vs. Sammy. While PII like an SSN will always need to be matched exactly. This is why Alloy offers both Matched (fuzzy matching) and Match Score (control how fuzzy or exact you want the matching to be) the List service.

Let’s start by looking at the difference between the two match-types. 

Matched Attribute (Fluid PII; Fuzzy Matching)

Matched attributes are boolean values (TRUE/FALSE) and use fuzzy matching by utilizing Jaro Winkler distance. Conceptually, you can think of fuzzy matching as being similar enough to the matching-target, but not necessarily an exact match. Examples of fluid data are names and addresses, where some variance can still mean the same person or location.

Example: You want to automatically deny an application with the name Will Williams, but the applicant submits using full name Willy Williams. Using Matched logic will allow you to flag this very close, but not exact match that could be expected with fluid PII like names.

Match Score Attribute (Non-Fluid PII; Exact Matching)

Match Score is more granular and offers more control in how fuzzy or how close to exact to match the data. A Match Score equal to 1 will require an exact match and is best for data that would rarely change or have variance -- e.g., like phone numbers or SSN. 

Example: You want to automatically deny an application with a specific SSN. Using Match Score=1 will require an exact match and will only flag when that condition is met. 

Now let’s look at these concepts within a workflow. In this example, the Workflow uses Alloy List Service Denylist with two rules; which can set a tag named Denylist Denied.

Tag Denylist Denied would be set if A) a “close enough” match against Denylist full name is found (Matched logic) OR B) and exact match (Match Score=1) against Denylist SSN is found. Fluid data like first name should use Matched (fuzzy) and static data like SSN should use Match Score=1.

To learn how to add Alloy List Service to your workflow click here.