Systems and methods for trusted path secure communication
A system for establishing a trusted path for secure communication between client devices and server devices, such as between an account holder and a financial institution, can provide the core security attributes of confidentiality (of the parties), integrity (of the information), anti-replay (protection against replay fraud) and/or anti-tampering (protection against unauthorized changes to information being exchanged and/or modules that generate and communicate such information). A messaging layer implementation in favor of a transport layer implementation can provide a trusted path. This infrastructure features secure cryptographic key storage, and implementation of a trusted path built using the cryptographic infrastructure. The trusted path protects against unauthorized information disclosure, modification, or replays. These services can effectively protect against Man-in-the-Middle, Man-in-the-Application, and other attacks.
1 . A method for secure exchange of information on a network between a client device and a server on a network, the method comprising:
encrypting, by a data-collection application or a security application associated with the data-collection application on the client device, a data element using a server public key to generate on the client device a secured object,
receiving, by the server, the secured object, wherein the secured object comprises an encrypted message used by the server to authenticate the client device, wherein the encrypted message comprises within the encrypted information at least a timestamp of the time the secured object was composed, a message identifier, a digital signature of the secured object signed by a private key on the client device, and a message digest comprising at least one or more of an anti-replay header and an anti-tamper header;
decrypting, by the server, the encrypted message;
validating, by the server, the digital signature of the decrypted message using a public key associated with the client device;
determining, by the server and the timestamp of the secured object, that the secured object was previously received more than a set threshold period of time before the time of receipt, or when an identifier cache at the server already contains the identifier or contents of the anti-replay header of that secured object;
determining, by the server, that one or more applications on the client device were altered when a message digest at the server does not match the message digest of the secured object as is expected to be produced by untampered versions of those applications on the client device;
discarding the secured object when the digital signature of the secured object cannot be verified, or when the secured object is determined to have been received prior to the set threshold period, or when the message is determined to have been replayed, or when the one or more applications on the client device were determined to be altered, and if the object is not discarded, then,
preparing, by the server, a download in reply to a validated secured object from the client device;
digitally signing, by the server's private key, the download to the client device;
encrypting the download, by the server, using the public key associated with the client device; and
receiving, by the client device, the signed and encrypted download.
2 . The method of claim 1 , further comprising: determining that the timestamp of the secured object corresponds to a time that is later than the current time.
3 . The method of claim 1 , further comprising: clearing, by the server, the identifier cache after a specified time period has passed.
4 . The method of claim 1 wherein the encrypted message further comprises an encrypted message history, the message history comprising a list of previously sent message identifiers and timestamps, wherein each timestamp corresponds to each of the previously sent message identifiers.
5 . The method of claim 4 , wherein determining that the secured object was previously received further comprises: comparing, by the server, the message history of the encrypted message to an expected message history at the server or client device based upon previously received messages;
determining, by the server, that the secured object was previously received when the expected message history does not match the message history of the encrypted message.
6 . The method of claim 5 , further comprising:
removing, by the server, a previously received message identifier and a corresponding timestamp from the expected message history when a difference between the corresponding timestamp and the current time exceeds a specified removal threshold.
7 . The method of claim 1 , further comprising:
sending, when the secured object was determined to be previously received or when the one or more applications on the client device were determined to be altered, a message to the client device that the secured object was discarded.
8 . A system, comprising:
a memory; and
at least one processor coupled to the memory and configured to:
encrypt, by a data-collection application or a security application associated with the data-collection application on the client device, a data element using a first level storage key to generate a secured object, wherein the first level storage key comprises at least one of:
(i) a public key of the server, the public key for encrypting information to be received by the data-collection application in a transmission from the server;
(ii) a private key of the data-collection application, the private key of the data-collection application for generating a signature for the information to be transmitted to the server from the client device;
(iii) a public key of the data-collection application, the public key of the data-collection application for encrypting information to be transmitted from the client device to the server; and
(iv) a private key of the server, the private key of the server generating a signature for information to be transmitted to the client device from the server;
receive on the server the secured object, wherein the secured object comprises an encrypted message used by the server to authenticate the client device, wherein the encrypted message comprises within the encrypted information at least a timestamp of the time the secured object was composed, a message identifier, a digital signature of the secured object signed by a private key of the client device, and a message digest comprising at least one or more of an anti-replay header and an anti-tamper header;
decrypt, by the server, the encrypted message;
validate the digital signature of the decrypted message using a public key associated with the client device;
determine, by the server and the timestamp of the secured object, that the secured object was previously received more than a set threshold period of time before the time of receipt or when an identifier cache at the server already contains the identifier or contents of the anti-replay header of the secured object; determine, by the server, that one or more applications on the client device were altered when a message digest at the server does not match the message digest of the secured object as is expected to be produced by untampered versions of those applications on the client device; and
discard the secured object when the digital signature of the secured object cannot be verified or when the secured object is determined to have been received prior to the set threshold period, or when the message is determined to have been replayed or when the one or more applications on the client device were determined to be altered and if the object is not discarded, then
preparing by the server, a download in reply to a validated secured object from the client device;
digitally signing, by the server private key, the download to the client device;
encrypting the download, by the server, using the public key associated with the client device; and
receiving, by the client device, the signed and encrypted download.
9 . The system of claim 8 , wherein the at least one process is further configured to: determine that the timestamp of the secured object corresponds to a time that is later than the current time.
10 . The system of claim 8 , wherein the at least one process is further configured to: clear the identifier cache after a specified time period has passed.
11 . The system of claim 8 , wherein the encrypted message further comprises an encrypted message history, the message history comprising a list of previously sent message identifiers and timestamps, wherein each timestamp corresponds to each of the previously sent message identifiers.
12 . The system of claim 11 , wherein to determine that the secured object was previously received, the at least one processor is further configured to:
compare the message history of the encrypted message to an expected message history based upon previously received messages at the server or client device;
determine that the secured object was previously received when the expected message history does not match the message history of the encrypted message.
13 . The system of claim 12 , wherein the at least one process is further configured to:
remove a previously received message identifier and a corresponding timestamp from the expected message history when a difference between the corresponding timestamp and the current time exceeds a specified removal threshold.
14 . A non-transitory computer-readable device having instructions stored thereon that, when executed by at least one computing device, causes the at least one computing device to perform operations comprising:
encrypting, by a data-collection application or a security application associated with the data-collection application on the client device, a data element using a server public key to generate on the client device a secure secured object,
to the client device from the server:
receiving, by a server, the secured object, wherein the secured object comprises an encrypted message used by the server to authenticate a client device, wherein the encrypted message comprises within the encrypted information at least a timestamp of the time the secured object was composed, a message identifier, a digital signature of the secured object signed by a private key on the client device, and a message digest comprising at least one of an anti-replay header and an anti-tamper header;
decrypting, by the server, the encrypted message;
validating, by the server, the digital signature of the decrypted message using a public key associated with the client device;
determining, by the server and the timestamp of the secured object, that the secured object was previously received more than a set threshold period of time before the time of receipt, or when an identifier cache at the server already contains the identifier or contents of the anti-replay header of the secured object of that secured object;
determining, by the server, that one or more applications on the client device were altered when a message digest at the server does not match the message digest of the secured object as is expected to be produced by untampered versions of those applications on the client device;
discarding the secured object when the digital signature of the secured object cannot be verified or when the secured object is determined to previously have been received prior to the set threshold period or when the message is determined to have been replayed or when the one or more applications on the client device were determined to be altered, and if the object is not discarded, then
preparing, by the server, a download in reply to a validated secured object from the client device;
digitally signing, by the server private key, the download to the client device;
encrypting the download, by the server, using the public key associated with the client device; and
receiving, by the client device, the signed and encrypted download.
15 . The non-transitory computer-readable device of claim 14 , the operations further comprising:
determining that the timestamp of the secured object corresponds to a time that is later than the current time.
16 . The non-transitory computer-readable device of claim 14 , the operations further comprising:
clearing, by the server, the identifier cache after a specified time period has passed.
17 . The non-transitory computer-readable device of claim 14 , wherein the encrypted message further comprises an encrypted message history, the message history comprising a list of previously sent message identifiers and timestamps, wherein each timestamp corresponds to each of the previously sent message identifiers.
18 . The non-transitory computer-readable device of claim 17 , wherein determining that the secured object was previously received further comprises:
comparing, by the server, the message history of the encrypted message to an expected message history at the server or client device based upon previously received messages;
determining, by the server, that the secured object was previously received when the expected message history does not match the message history of the encrypted message.
19 . The non-transitory computer-readable device of claim 18 , the operations further comprising:
removing, by the server, a previously received message identifier and a corresponding timestamp from the expected message history when the difference between the corresponding timestamp and the current time exceeds a specified removal threshold.
20 . The non-transitory computer-readable device of claim 14 , the operations further comprising:
sending, when the secured object was determined to be previously received or when the one or more applications on the client device were determined to be altered, a message to the client device that the secured object was discarded.