Optimized key management for data signing systems
A system and method for providing a providing security credential is disclosed. In one embodiment, the method comprises accepting a request to generate at least one key in an online data signing system; generating, in a hardware security module communicatively coupled to the online data signing system, a first key K 1 as a temporary object; encrypting, by the hardware security module, the first key K 1 according to a wrapping key Kw to produce an encrypted first key E Kw [K 1 ]; storing the encrypted first key; and providing a second key K 2 associated with the first key K 1 to a user device communicatively coupled to the online data signing system.
1. A method of providing security credentials, comprising:
accepting a request to generate at least one key in an online data signing system;
generating, in a hardware security module communicatively coupled to the online data signing system, a first key K 1 as a temporary object;
encrypting, by the hardware security module, the first key K 1 according to a wrapping key Kw to produce an encrypted first key E Kw [K 1 ];
storing the encrypted first key;
providing a second key K 2 associated with the first key K 1 to a user device communicatively coupled to the online data signing system;
linking, in the online data signing system, a configuration defined by an administrator to the encrypted first key E Kw [K 1 ];
accepting, in the online data signing system, a request from the user device to perform a cryptographic operation on data according to the configuration;
retrieving the encrypted first key;
decrypting, in the hardware security module, the encrypted first key according to the wrapping key Kw to recover the first key K 1 as a second temporary object;
performing the cryptographic operation on the data in the online data signing system according to the first key K 1 ; and
providing a result of the cryptographic operation to the user device.
2. The method of claim 1 , wherein the first key K 1 is volitively stored in the hardware security module as a session object.
3. The method of claim 1 , wherein:
the first key K 1 is a private key K Pr ; and
the second key K 2 is a public key K pu .
4. The method of claim 3 , wherein:
the public key K pu is generated by the online data signing system at least in part from the private key K Pr .
5. The method of claim 3 , further comprising:
generating, in the online data signing system, a digital certificate corresponding to the private key K Pr ; and
providing the public key K Pu to the user device comprises providing the digital certificate having the public key K Pu to the a user device.
6. The method of claim 3 , further comprising:
generating a certificate signing request according to the public key K Pu ;
providing the generated certificate signing request from the online data signing system to the an administrator;
receiving a digital certificate from the administrator, the digital certificate procured from a certificate authority in response to the certificate signing request;
associating the received digital certificate with the private key K Pr ; and
storing the received digital certificate.
7. The method of claim 6 , wherein:
the digital certificate is uploaded by an administrator to the online data signing system; and
the method further comprises:
linking, in the online data signing system, a configuration defined by the administrator to the digital certificate;
receiving data to be signed from the user device; and
providing a data package having a signature of data and the digital certificate to the user device.
8. The method of claim 6 , wherein:
the user device packages a signature of data obtained from the online data signing system together with the received digital certificate generate a signed data image for use by a target client system.
9. The method of claim 1 , wherein:
the cryptographic operation performed is a digital signing operation that can be validated using the second key.
10. The method of claim 1 , wherein:
the cryptographic operation is an encryption of the data, the encrypted data decryptable using the second key.
11. The method of claim 1 , wherein:
the decrypted first key is erased from the hardware security module following the performance of the cryptographic operation.
12. The method of claim 1 , wherein:
the decrypted first key K 1 is retained as a temporary object in a volatile memory of the hardware security module following the performance of the cryptographic operation; and
the decrypted first key K 1 retained in volatile memory is reused for further cryptographic operations.
13. The method of claim 1 , wherein:
accepting a request to generate at least one key in the online data signing system comprises:
accepting a request to generate a plurality of keys in the online data signing system;
generating, in a hardware security module communicatively coupled to the online data signing system, a first key K 1 as a temporary object comprises:
generating, in the hardware security module communicatively coupled to the online data signing system, a plurality of first keys (K 1,1 , K 1,2 , . . . K 1,n ) as temporary objects;
encrypting, by the hardware security module, the first key K 1 according to a wrapping key Kw to produce an encrypted first key E Kw [K 1 ] comprises:
encrypting, by the hardware security module, each of the plurality of first keys (K 1,1 , K 1,2 , . . . K 1,n ) according to a global wrapping key Kw to produce a plurality of encrypted first keys E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ];
storing the encrypted first key comprises:
storing the plurality of encrypted first keys E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ]; and
linking, in the online data signing system, a configuration defined by an administrator to the encrypted first key E Kw [K 1 ] comprises:
linking, in the online data signing system, a configuration defined by an administrator to each of the plurality of encrypted first keys E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ];
retrieving the encrypted first key comprises:
retrieving the plurality of encrypted first keys E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ];
decrypting, in the hardware security module, the encrypted first key according to the wrapping key Kw to recover the first key K 1 as a second temporary object comprises:
decrypting, in the hardware security module, each encrypted first key E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ] according to the global wrapping key Kw to recover each first key (K 1,1 , K 1,2 , . . . K 1,n ) as an additional temporary object; and
performing a cryptographic operation on the data in the online data signing system according to the first key K 1 comprises:
performing the cryptographic operation on data with each first key (K 1,1 , K 1,2 , . . . K 1,n ) in the online data signing system.
14. The method of claim 13 , wherein:
the decryption of each encrypted first key E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ] is performed during startup and initialization of the online data signing system.
15. The method of claim 13 , wherein:
the method further comprises accepting, in the online data signing system, a request from the user device to perform a cryptographic operation on the data according to the configuration; and
the decryption of each encrypted first key E Kw [K 1,1 ], E Kw [K 1,2 ,] . . . E Kw [K 1,n ] is performed in response to the accepting of the request from the user device.
16. The method of claim 1 , wherein:
the first key K 1 is a symmetric randomly generated key; and
the second key K 2 is identical to the first key.
17. An apparatus for providing security credentials, comprising:
a processor;
a memory, communicatively coupled to the processor, the memory storing processor instructions comprising processor instructions for:
accepting a request to generate at least one key in an online data signing system;
generating, in a hardware security module communicatively coupled to the online data signing system, a first key K 1 as a temporary object;
encrypting, by the hardware security module, the first key K 1 according to a wrapping key Kw to produce an encrypted first key E Kw [K 1 ];
storing the encrypted first key;
providing a second key K 2 associated with the first key K 1 to a user device communicatively coupled to the online data signing system;
linking, in the online data signing system, a configuration defined by an administrator to the encrypted first key E Kw [K 1 ];
accepting, in the online data signing system, a request from the user device to perform a cryptographic operation on data according to the configuration;
retrieving the encrypted first key;
decrypting, in the hardware security module, the encrypted first key according to the wrapping key Kw to recover the first key K 1 as a second temporary object;
performing the cryptographic operation on the data in the online data signing system according to the first key K 1 ; and
providing a result of the cryptographic operation to the user device.
18. The apparatus of claim 17 , wherein:
the first key K 1 is a private key K Pr ;
the second key K 2 is a public key K pu ;
the processor instructions further comprise processor instructions for:
generating, in the online data signing system, a digital certificate corresponding to the private key K Pr ; and
providing the public key K Pu to the user device comprises providing the digital certificate having the public key K Pu to a user device.
19. The apparatus of claim 18 , wherein:
the first key K 1 is a private key K Pr ;
the second key K 2 is a public key K pu ;
the processor instructions further comprise processor instructions for:
generating a certificate signing request according to the public key K Pu ;
providing the generated certificate signing request from the online data signing system to the an administrator;
receiving a digital certificate from the administrator, the digital certificate procured from a certificate authority in response to the certificate signing request;
associating the received digital certificate with the private key K Pr ; and
storing the received digital certificate.