About Answer Logic Adjusting Answer Logic

Managing Knowledge-Based Authentication 7-31 ■ Switching t and r Examples of Fat Fingering ■ Correct word: signature - Fat finger: signatire

7.9.3 Level of Answer Logic

The level of Answer Logic, the intensity or strength of algorithms, used to evaluate answers given for challenge questions is adjustable. You can enable or disable each algorithm and you can also specify the following levels for the algorithms used: ■ Off – No Answer Logic is used; answers must exactly match those previously registered by the user. ■ Low – Less Answer Logic; answers provided by the user must be a match or near-match to the answers that were provided at the time of registration ■ Medium – More Answer Logic; the user is given some leeway for the answers that are provided. For example, St. might be accepted for Street. ■ High – Highest level of Answer Logic. The constraints are not strict for matching. Each algorithm generates a score that represents how close the given answer is to the registered answer. OAAM Admin can be configured to accept different threshold score ranges for each algorithm individually. Separate threshold values for each algorithm lowmediumhigh are set in a properties file. The default thresholds are described as follows.

7.9.3.1 Abbreviation

For abbreviation: ■ Return values: 0 or 100 no-match OR match ■ Levels: ON or OFF ■ Logic – If an abbreviation entry exists linking the given strings, score is 100 – Else score is 0

7.9.3.2 Fat Fingering

For fat fingering: ■ Return values: range 0 to 100 ■ Levels: OFF, LOW 90+, MEDIUM 75+, HIGH 60+ ■ Logic – If the string lengths do not match, score is 0 – If a position does not have the expected character or its neighbor, score is 0 – Else compute the number of positions that have the neighboring characters. – Score = StringLength – NeighborPositionCount 100 StringLength

7.9.3.3 Phonetics

For phonetics: ■ Return values: 0, 60, 75, 90 7-32 Oracle Fusion Middleware Administrators Guide for Oracle Adaptive Access Manager ■ Levels: OFF, LOW 90, MEDIUM 75, HIGH 60 ■ Logic – Compute primary and alternative phonetic keys for the given strings, using DoubleMetaphone algorithm – If primary keys of both strings match, score is HIGH – Else if a primary key of one of the strings and alternate key of the other string match, score is MEDIUM – Else if the alternate keys of both string match, score is LOW – Else the score is 0

7.9.3.4 Multiple Word Answers

Answers that contain multiple words are treated in a specific way by the Answer Logic. If the final score from a complete string match does not meet the success criteria, individual words in the answer are evaluated. If each individual word in an answer is accepted by any of the algorithms the whole answer is accepted. Multiple word answers with missingextra words must be an exact match to the registered answer. Answers must have the same number of words as the registered answer to be evaluated with Answer Logic. For example: If the registered answer is Mead Elementary School and the answer given at the time of challenge is Mesd Elem Sch: Abbreviation: Mead–Mesd=0; Elementary-Elem=100; School-Sch=100 Fat-finger: Mead-Mesd=75; Elementary-Elem=0; School-Sch=0 Phonetics: Mead-Mesd=0; Elementary-Elem=0; School-Sch=0 Assuming that abbreviation was set to anything besides off and fat fingering was set to medium or high, since all three words would be accepted individually, the whole answer would be accepted.

7.9.4 Configuring Answer Logic

The KBA Answer Logic tab includes controls for the level of each Answer Logic algorithm used for answer validation. The higher the level the less exact answers need to be for acceptance. To configure Answer Logic:

1. In the Navigation tree, double-click Answer Logic under KBA.

You can specify different settings for Online Challenge and CSR Phone Challenge.