Protecting account security settings using strong proofs

1. A method comprising:

under control of one or more computer processors configured with executable instructions:

receiving a request to change a security setting of an account of a user, wherein the account includes multiple strong proofs each being associated with one of multiple tiers of proofs;

attempting to confirm the request by notifying, using a strong proof of the account, the user;

permitting the change if the request is confirmed; and

keeping the security setting unchanged if the request is not confirmed.

2. A method as recited in claim 1 , wherein the security setting is a password of the account.

3. A method as recited in claim 1 , wherein the security setting is a first strong proof of the multiple strong proofs, and wherein the attempting comprises attempting to confirm the request by notifying, using one or more of the multiple strong proofs that are at a higher tier than the first strong proof, the user.

4. A method as recited in claim 1 , wherein the security setting is a first strong proof of the multiple strong proofs, and wherein the attempting comprises attempting to confirm the request by notifying, using two or more of the multiple strong proofs that are at a lower tier than the first strong proof, the user.

5. A method as recited in claim 1 , wherein the request comprises a request to add an additional strong proof to a set of multiple strong proofs associated with the account.

6. A method as recited in claim 1 , wherein multiple strong proofs are associated with the account, the method further comprising:

receiving an indication that all of the multiple strong proofs have been lost;

communicating, for each of the multiple strong proofs, a notification using the strong proof;

keeping each of the multiple strong proofs as a strong proof if a response to one or more of the notifications is received within a threshold amount of time; and

expiring each of the multiple strong proofs if no response to the notifications is received within the threshold amount of time.

7. A method as recited in claim 1 , further comprising:

identifying that the account is a pre-existing account of the user; and

automatically identifying, in response to the account being identified as a pre-existing account, each of multiple proofs of the pre-existing account as a strong proof associated with the account.

8. A method as recited in claim 1 , further comprising:

identifying a first proof associated with the account as a strong proof, and identifying each of one or more additional proofs associated with the account as an additional strong proof only if the additional proof is confirmed, using another strong proof, as to be added as the additional strong proof.

9. A method as recited in claim 1 , further comprising permitting access to a service associated with the account despite the change being denied.

10. A method as recited in claim 1 , wherein the strong proof of the account comprises an email address of the user.

11. A method as recited in claim 1 , wherein the strong proof of the account comprises a wireless phone number of the user.

12. A method as recited in claim 1 , wherein the strong proof of the account comprises a secret key of a smartcard of the user.

13. One or more computer hardware storage devices having stored thereon multiple instructions that, when executed by one or more processors of one or more computing devices, cause the one or more processors to:

maintain both a password and multiple strong proofs associated with an account of a user, wherein each of the multiple strong proofs is associated with one of multiple tiers of proofs;

receive a request to change the password; and

permit the requested change to the password only if the change is confirmed via one or more of the multiple strong proofs.

14. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple instructions further cause the one or more processors to:

receive a request to change a first strong proof of the multiple strong proofs;

attempt to confirm the request by sending one or more notifications, using one or more of the multiple strong proofs that are at a higher tier than the first strong proof, to the user; and

permit the requested change to the first strong proof only if a confirmation of the requested change to the first strong proof is received from the user in response to the one or more notifications.

15. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple instructions further cause the one or more processors to:

receive a request to change a first strong proof of the multiple strong proofs, wherein each of the multiple strong proofs is associated with one of multiple tiers of proofs;

attempt to confirm the request by sending one or more notifications, using two or more of the multiple strong proofs that are at a lower tier than the first strong proof, to the user; and

permit the requested change to the first strong proof only if a confirmation of the requested change to the first strong proof is received from the user in response to the one or more notifications.

16. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple instructions further cause the one or more processors to:

receive an indication that all of the multiple strong proofs have been lost;

send, for each of the multiple strong proofs, a notification using the strong proof;

keep each of the multiple strong proofs as a strong proof if a response to one or more of the notifications is received within a threshold amount of time; and

expire each of the multiple strong proofs if no response to the notifications is received within the threshold amount of time.

17. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple instructions further cause the one or more processors to:

identify that the account is a pre-existing account of the user; and

automatically identify, in response to the account being identified as a pre-existing account, each of multiple proofs of the pre-existing account as a strong proof associated with the account.

18. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple instructions further cause the one or more processors to permit access to a service associated with the account even if the requested change to the password is not permitted.

19. One or more computer hardware storage devices as recited in claim 13 , wherein the multiple strong proofs of the account comprise: a wireless phone number of the user, an email address of the user, and a secret key of a computing device of the user.

20. A system comprising:

one or more computer processors; and

one or more computer readable hardware storage devices, communicatively coupled to the one or more computer processors,

a user account information store embodied on the one or more computer readable hardware storage devices and configured to be used by the one or more computer processors to store both a password as a normal proof and multiple strong proofs associated with an account of a user; and

an account security control module embodied on the one or more computer readable hardware storage devices and configured to be used by the one or more computer processors to access the user account information store and to:

in response to a received request to change a strong proof of the multiple strong proofs,

attempt to confirm the request by notifying, using one or more of the multiple strong proofs, the user,

permit the change if the request is confirmed, and

keep the strong proof unchanged if the request is not confirmed; and

in response to a received indication that all of the multiple strong proofs have been lost,

communicate, using each of one or more of the multiple strong proofs, a notification using the strong proof,

keep each of the multiple strong proofs as a strong proof if a response to one or more of the notifications is received within a threshold amount of time, and

expire each of the multiple strong proofs if no response to the notifications is received within the threshold amount of time.