Monitor and Share Anonymized Data

Follow these steps to monitor and evaluate the anonymization used in your database:

1. Open the SAP BTP Cockpit.

2. Navigate to your global account, sub-account and space where your SAP HANA Cloud instance is located.

3. On the bottom right corner of the tile of your SAP HANA Cloud instance, click on Actions.

4. Select Open in SAP HANA Cockpit. The SAP HANA cockpit will open in a new tab.

   

5. In the SAP HANA cockpit, navigate to the section All or Security and User Management.

6. Navigate to the card Anonymization report.

7. Click on View available anonymization views.

   

1. There, you can see all reports available for your database. Each anonymized view has a corresponding report that is represented in one of the rows.

   

2. If you click on a report, you can see the anonymization method and parameters you have specified.

3. For example, if you have used the anonymization method of k-anonymity, you will see this reflected at the top area. Below, in the Supporting KPI’s area, you can see various KPI’s that will tell you more about the effectiveness of your anonymized view.

   

1. Supporting KPI’s

   You can click on each KPI to get detailed information on what they describe.

   

2. Column Overview

   Scrolling down, you can also find an overview of all columns in your anonymized view and what type you determined for them in the view.

   

3. Hierarchies defined

   For each quasi-identifier, you can also view the hierarchies defined. This works both for embedded hierarchies, as well as hierarchy functions.

   

4. KPI’s for differential privacy

   If you use differential privacy in your anonymized view, the KPI’s compiled in your report will vary.

   

To access the anonymization reports directly in the SAP HANA Database Explorer, you can use this statement:

GET_ANONYMIZATION_VIEW_STATISTICS('<action>', '[<parameters>]', '<schema_name>', '<view_name>')

For example, you can get the names and descriptions or values of the KPI’s available in your report by using the statement like this:

--names & descriptions
GET_ANONYMIZATION_VIEW_STATISTICS('get_names', NULL, '<schema_name>', '<view_name>')
--names & values
GET_ANONYMIZATION_VIEW_STATISTICS('get_values', NULL, '<schema_name>', '<view_name>')

There are four categories of KPI’s you can use to evaluate your anonymization:

• Static source KPI’s that reflect the source data.
• Static anonymization KPI’s that reflect the anonymized data.
• Dynamic utility KPI’s that reflect source data, anonymized data and the anonymization method and its parameters.
• Dynamic risk KPI’s that may include more parameters

You can learn more about the Anonymization KPI’s in the technical documentation here.

Making anonymized data available to others

One simple way to share an anonymized view directly in the SAP HANA Database Explorer is to give other users SELECT privileges to access it. You can do so using this command that needs to include the anonymized view name and the user:

GRANT SELECT ON <view_name> TO <user>;

If you are unsure how to create users in SAP HANA Cloud, SAP HANA database, read more here.

Another way to share an anonymized view is to make it available in other applications and dashboards. SAP Analytics Cloud offers great ways to visualize data in convenient dashboards. Note that data needs to be in a calculation view for SAP Analytics Cloud to consume it.
Usually, in SAP Analytics Cloud, users can drill down into the data as far as they want and apply filters. This could potentially result in a breach of privacy, e.g., if a category of values contains less people than specified by k-anonymity.

The following image shows how someone can drill down into the non-anonymized data and find out the information on specific individuals:

For Non-Anonymized Data

• From the above image, the highlighted option “drill down”, provides the functionality to narrow down the information to smaller categories.
• By applying various filters here, the number of persons associated with a particular set of information can be narrowed down to a single individual.

You can refer the video in the introduction of this tutorial for details.

When an anonymized view is shared via SAP Analytics Cloud, drilling down into certain categories and filtering is simply not possible. All data can still be analyzed on a group level – without the risk of a data consumer accidentally drilling down too far.

The following image shows how anonymized data can prevent someone from finding out the information on specific individuals:

For Anonymized Data

• From the above image, the highlighted options do not show the “drill down” option, meaning that existing information cannot be narrowed down further to smaller categories.
• Here, the number of persons associated with a particular information cannot be narrowed down to a single individual even after applying all the filters.

You can refer the video in the introduction of this tutorial for details.

That is all for this tutorial group. Let us recap what you have learned:

1. Data anonymization is important so you can analyze your data without the risk of violating data privacy regulations.
2. Data anonymization in SAP HANA Cloud uses anonymized views that always contain the latest data, leave the original data untouched and can be safely shared with others.
3. Using the method of k-anonymity, you can avoid that individuals are identified by quasi-identifiers, even if their names are removed.
4. To further protect sensitive data, you can either complement k-anonymity with l-diversity or add random noise to your data with differential privacy.
5. You can monitor KPI’s of your anonymized view in the SAP HANA cockpit and share anonymized data by giving access rights to other users or present the data in dashboards like with SAP Analytics Cloud.

Well done!

You have completed the last tutorial of this group!

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