Create a Calculation View with Differential Privacy in SAP Web IDE

Requires Customer/Partner License

Beginner

20 min.

SAP HANA service for SAP BTP, SAP HANA, Tutorial, Beginner

Use differential privacy to anonymize confidential data

You will learn

How to create Calculation View of type Cube using SAP Web IDE
How to configure differential privacy to add noise to a column

Thomas JungJanuary 27, 2021

Created byMay 23, 2019

Contributors

Prerequisites

This tutorial is designed for SAP HANA service for SAP Business Technology Platform. Consider newer tutorials designed for SAP HANA Cloud.
You have completed the previous tutorials to load data into the table TGT_SALARIES

This tutorial cannot be completed with a trial account.

Step 1
Create a new folder called models under db/src. Create a new Calculation View and call it SALARIES_ANONYMIZED
Click on the anonymization node and then click on the white canvas to drop it.
Use the
on the node to add a table as a data source. Choose TGT_SALARIES
Step 2
Double click on the Anonymize_1 node. This will open the mapping. Double click on TGT_SALARIES to add all of the columns to the output

Click Details and switch k-anonymity to Differential Privacy

Configure the following parameters for anonymity
Sequence Column: ID
Epsilon: 0.1
Sensitivity: 15000
Noised Column: SALARY

For example:

For more information about these parameters check the SAP HANA Security Guide
Step 3
Connect the Anonymize_1 node to the Aggregation node.
Double-click on the name of the node to move all the fields into the output columns.
Go into the Semantics node and switch START_YEAR to attribute
Step 4
Save and Build the calculation view
Right-click on it and choose Data Preview
Click Raw Data and you will see the anonymized data:
See the negative salaries? The added noise guarantees privacy while keeping sum and average results similar to the original dataset.
Use the Analysis tab and drag the GENDER and REGION fields to the label axis and ID to the Value axis.
Change the aggregation for SALARY to COUNT to answer the question below.
Which region has the highest number of female employees?
EMEA
APJ
NA
LATAM
Step 5
If you have a tenant in SAP Analytics Cloud or a reporting tool such as Analysis for Office, you can configure the SAP HANA Analytics Adapter. The adapter is a Java application that exposes Calculation Views for consumption through Information Access (or InA).
Follow the steps in the following blog post if you want to set up the HANA Analytics Adapter: https://blogs.sap.com/2019/04/24/connecting-the-sap-hana-service-on-cloud-foundry-to-sap-analytics-cloud-the-lazy-approach-pt1/