Scored factor-based authentication

1. A method comprising:

receiving, at a computing device that executes an authentication service, an authentication request from a requestor, wherein the authentication request identifies a transaction associated with the requestor;

determining, by the computing device, a risk associated with the transaction;

determining, by the computing device, an authentication score based upon the risk, wherein the authentication score comprises a level of nonrepudiation to be met during authentication to allow execution of the transaction;

determining, by the computing device, a plurality of groups of authentication factors, wherein each of the plurality of groups of authentication factors meets the authentication score; and

providing, by the computing device, factor group data identifying the plurality of groups of authentication factors to the requestor, wherein one of the plurality of groups of authentication factors comprises a plurality of authentication factors determined based upon a product of a relative strength and a nonrepudiation aspect strength determined for each of the plurality of authentication factors.

2. The method of claim 1 , wherein determining the authentication score comprises analyzing the risk and analyzing score data to determine the authentication score.

3. The method of claim 1 , wherein the one of the plurality of groups of authentication factors comprises a plurality of authentication factors determined based upon a product of relative strength and a nonrepudiation aspect strength determined for each of the plurality of authentication factors.

4. The method of claim 1 , wherein determining the risk associated with the transaction comprises:

analyzing authentication data to determine the risk based upon an identification of the transaction included in the authentication request and a transaction definition included in the authentication data.

5. The method of claim 1 , wherein the requestor comprises a web server that hosts a web application, and wherein the transaction comprises an action executed by the web application.

6. The method of claim 1 , further comprising: receiving, by the computing device, data input comprising a factor group choice and responses associated with the authentication factors; determining, by the computing device, if the data input meets an authentication requirement; and providing, by the computing device, an authentication result to the requestor.

7. The method of claim 1 , further comprising:

receiving, by the computing device, authentication data from an authentication data source; and

storing, by the computing device, the authentication data at a data store.

8. The method of claim 7 , wherein the authentication data comprises

risk data that defines the transaction and the risk associated with the transaction,

factor data defining authentication factors, and

score data defining how the authentication score is determined based upon the risk determined.

9. A system comprising:

a processor; and

a memory that stores computer-executable instructions that, when executed by the processor, cause the processor to perform operations comprising:

receiving an authentication request from a requestor, wherein the authentication request identifies a transaction associated with the requestor;

determining a risk associated with the transaction;

determining an authentication score based upon the risk, wherein the authentication score comprises a level of nonrepudiation to be met during authentication to allow execution of the transaction;

determining a plurality of groups of authentication factors, wherein each of the plurality of groups of authentication factors meets the authentication score; and

providing factor group data identifying the plurality of groups of authentication factors to the requestor, wherein one of the plurality of groups of authentication factors comprises a plurality of authentication factors determined based upon a product of a relative strength and a nonrepudiation aspect strength determined for each of the plurality of authentication factors.

10. The system of claim 9 , wherein the requestor comprises a web server that hosts a web application, and wherein the transaction comprises an action executed by the web application.

11. The system of claim 9 , wherein the requestor comprises a user device that accesses an authentication service.

12. The system of claim 9 , wherein the computer-executable instructions, when executed by the processor, cause the processor to perform operations further comprising: receiving data input comprising a factor group choice and responses associated with the authentication factors; determining if the data input meets an authentication requirement; and providing an authentication result to the requestor.

13. The system of claim 9 , further comprising an authentication data source and a data store.

14. The system of claim 13 , wherein the computer-executable instructions, when executed by the processor, cause the processor to perform operations further comprising:

receiving authentication data from the authentication data source; and

storing the authentication data at the data store.

15. A computer storage medium having computer-executable instructions stored thereon that, when executed by a processor, cause the processor to perform operations comprising:

receiving an authentication request from a requestor, wherein the authentication request identifies a transaction associated with the requestor;

determining a risk associated with the transaction;

determining an authentication score based upon the risk, wherein the authentication score comprises a level of nonrepudiation to be met during authentication to allow execution of the transaction;

determining a plurality of groups of authentication factors, wherein each of the plurality of groups of authentication factors meets the authentication score; and

providing factor group data identifying the plurality of groups of authentication factors to the requestor, wherein one of the plurality of groups of authentication factors comprises a plurality of authentication factors determined based upon a product of a relative strength and a nonrepudiation aspect strength determined for each of the plurality of authentication factors.

16. The computer storage medium of claim 15 , wherein the computer-executable instructions, when executed by the processor, cause the processor to perform operations further comprising: receiving data input comprising a factor group choice and responses associated with the authentication factors; determining if the data input meets an authentication requirement; and providing an authentication result to the requestor.

17. The computer storage medium of claim 16 , wherein the authentication requirement comprises a further level of nonrepudiation, and wherein the further level of nonrepudiation is based upon the authentication score.

18. The computer storage medium of claim 15 , wherein the computer-executable instructions, when executed by the processor, cause the processor to perform operations further comprising:

receiving authentication data from an authentication data source; and

storing the authentication data at a data store.

19. The computer storage medium of claim 15 , wherein the computer-executable instructions, when executed by the processor, cause the processor to perform operations further comprising receiving data input comprising:

information identifying a factor group choice made via a user interface presented at a user device in communication with the requestor; and

information corresponding to responses associated with a plurality of authentication factors associated with an authentication factor group associated with the factor group choice.