ANONYMITY MEASURING DEVICE

• US 20100169332A1
• Filed: 01/25/2008
• Published: 07/01/2010
• Est. Priority Date: 01/29/2007
• Status: Active Grant

• Current Assignee: Accenture Global Services Limited (Accenture PLC)
• Original Assignee: Accenture Global Services GmbH (Accenture PLC)
• Inventors: Bezzi, Michele
• Granted Patent: US 8,407,246 B2
• Time in Patent Office: Days
• US Class Current: 707/757
• CPC Class Codes: G06F 16/24 Querying
• CPC Class Codes: G06F 21/6245 Protecting personal data, e.g. for financial or medical purposes

Abstract

The invention concerns a data anonymity measuring device for selectively transmitting an anonymised database to a third party comprising: calculation means (402) coupled to at least one memory, the memory storing an original database (204) and said anonymized database (206), said calculation means arranged to calculate the conditional entropy for each entry in said anonymized database based on entries in said original database; comparing means (406) arranged to compare at least one of said conditional entropies with a threshold value; and output means (410) arranged to transmit said anonymized database based on the result of said comparison.

Claims

1. A data anonymity measuring device for selectively transmitting an anonymised database to a third party comprising:

a calculation unit (402) coupled to at least one memory (204, 206), the memory storing an original database and said anonymized database, said calculation unit arranged to calculate the conditional entropy for each entry in said anonymized database based on entries in said original database;

a comparator (406) arranged to compare at least one of said conditional entropies with a threshold value; and

an output unit (410) arranged to transmit said anonymized database based on the result of said comparison.

2. The anonymity measuring device of claim 1, wherein said calculation unit is arranged to calculate said conditional entropy based on the probability of each entry in the original database given an entry in the anonymized database.

3. The anonymity measuring device of claim 1, wherein said calculation unit is arranged to calculate said conditional entropy (h(s)) according to the following formula:

4. The anonymity measuring device of claim 1, further comprising a minimum entropy determination unit (404) arranged to determine a minimum entropy of said conditional entropies, and wherein said comparator is arranged to compare said minimum conditional entropy with said threshold value.

5. A selective transmission device for selectively transmitting an anonymized database to a third party comprising the anonymity measuring device of any preceding claim.

6. The selective transmission device of claim 5, comprising circuitry for erasing said anonymized database from said memory under the control of said anonymity measuring device if one or more of said conditional entropies is lower than said threshold value.

7. A method for selectively transmitting an anonymized database to a third party, the method comprising:

for each entry in said anonymized database, determining the conditional entropy based on entries in an original database;

comparing at least one of said conditional entropies with a threshold entropy value; and

selectively transmitting said database to said third party based on the result of said comparison.

8. The method of claim 7, wherein said conditional entropy is calculated based on the probability of each entry in said original database given an entry in said anonymized database.

9. The method of claim 7, wherein in said comparison step said at least one conditional entropies is a minimum conditional entropy of said condition entropy values, and wherein said anonymized database is transmitted to said third party if said minimum conditional entropy is greater than said threshold entropy value.

10. The method of claim 7, wherein said step of determining said conditional entropy for each entry in said anonymized database comprises the step of, for each entry in said original database, calculating the cumulative entropy (h) using the following formula:

h=h−

P(r_a|S_b)log₂ P(r_a|S_b)

wherein r_a is a currently processed entry in the original database, s_b is the currently processed entry in the anonymized database.

11. The method of claim 9, wherein, if said minimum entropy is less than said threshold value, further anonymizing said anonymized database.

12. A computer program comprising preprogrammed instructions for causing a processor to execute the method of any of claims 7 to 11.