GB2510378A

GB2510378A - Simultaneously providing caller ID information and encrypted caller ID information for Telephony caller authentication

Info

Publication number: GB2510378A
Application number: GB1301781.9A
Authority: GB
Inventors: Andrew Stewart Feltham; Elizabeth Jane Maple; Simon James Maple
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 2013-02-01
Filing date: 2013-02-01
Publication date: 2014-08-06
Also published as: GB201301781D0

Abstract

A method of providing Caller ID information in a telephone call, the method comprising: encrypting 104 Caller Identification information; initiating 108 the telephone call, said initiating comprising: providing 108a a voice carrier signal including the caller ID information; and simultaneously providing 108b a data carrier signal including the encrypted caller ID information. Aspects of the invention include the receiving device receiving (204) the telephone call; decrypting (206) the encrypted caller identification information at the recipient device; and verifying the identity of at least an unknown caller at the recipient device by at least one of verifying the authenticity of a certificate used to encrypt the caller identification information; and comparing (208) the decrypted caller identification information with the caller identification information from the voice carrier signal. A telephony device (500) implementing such an authentication method is also disclosed.

Description

TELEPHONY CALLER AUTHENTICATION

FIELD OF THE INVENTION

The present invention re'ates to a method of authenticating the identity ofa cafler in a telephone call between a caller device and a recipient device, the method comprising including caller identification information in a voice carrier signal from the caller device.

The present invention ifirther relates to a telephony device for use in such a method.

BACKGROUND

Ill modern society, many financial transactions are now performed electronically, e.g. using credit or debit cards, by performing transactions over the Internet and/or by using mobile telephony protocols to name but a few examples. The authenticity of such transactions is typically ensured by thc USC of somc ycrification data that can only be known to the user, c.g.

(selected characters from) passwords and so on.

Nevertheless, such transactions can be sensitive to fraud, e.g. because credit or debit card details have been stolen or because the security of user authentication information has been compromised. Fortunately, many financial institutions, e.g. banks, perfoim rigorous security checks on most financial transactions, and contact a customer in case a particular transaction cannot be trusted. Such contact is typically performed by telephone, with the call being initiatcd by an employee of the financial institution asking thc customer to divulgc details of the customer's security information in order to verify the ideiltity of the customer.

However, such contact itself is susceptible to fraud. A customer may be contacted maliciously over the telephone by a caller posing as an employee of a financial institution in order to obtain the security details of the customer with the intention to defraud the customer by engaging in financial transactions using the customer's funds. It can be very difficult to detect such malicious calls. The caller ID may be withheld, or may be fraudulently altered (spoofed), as is known per se; see e.g.: http://www.docdronnersorc/wikilindex.plip'hitle=AN] and Caller II) Spooling. Although a vigilant customer may verify the identity of the caller by requesting a phone number that the customer can call back and subsequently contact the financial institution to veri' if the provided phone number can be trusted, this is rather cumbersome and does not avoid the risk of a customer erroneously trusting the identity of a malicious caller.

Attempts have been made to facilitate the recipient of a call to establish the authenticity of the caller. For instance, US 2011/0026699 Al discloses a service that handles incoming telephone calls without bothering the telephone subscriber. The service permits a call to go through to a subscriber if the service determines that the call is not unwanted and the caller has been unauthenticated. The authentication is based on challenging the caller to prove its identity rather than relying on caller ID displays. Prospective callers pre-register with the service providing caller account information. When a caller is issued a challenge, the caller may prove its authenticity by supplying the challenge back to the service along with its registered information. Although this service avoids a subscriber being subjected to unwanted and fraudulent calls, a disadvantage of this approach is that it requires active implementation by a service provider and several process steps before a caller can be connected to a subscriber.

BRIEF SUMMARY OF THE INVENTION

The present invention seeks to provide a more straightforward method of authenticating the identity of a caller in a telephone call between a caller device and a recipient device.

The present invention further seeks to provide a telephony device that can implement at least certain aspects of this method.

According to an aspect of the present invention, there is provided a method of providing caller identification information in a telephone call, the method comprising encrypting caller identification information; initiating the telephone call, said initiating comprising: providing a voice carrier signal including the caller identification information; and simultaneously providing a data carrier signal including the encrypted caller identification information.

This allows a recipient of such a call to authenticate the identity of the caller by comparison of the encrypted caller identification information provided in the data carrier signal, e.g. in the form of a message, with the unencrypted caller identification information provided in the voice carrier signal, thus facilitatillg a straightforward caller identification authentication method does not require service provider intervention.

In a preferred cmbodimcnt, thc caflcr idcntification information is encrypted using a privatc key.

According to another aspect of the present invention there is provided a method of authenticating the identity of a caller in a telephone call between a caller device and a recipient device, the method comprising receiving a telephone call initiated by a caller device in accordance with the aforementioned method of providing caller identification information in a telephone call; decrypting the encrypted caller identification information at the recipient device; and vcrifring thc identity of at lcast an unknown caller at the rccipicnt dcvicc by at least one of verifying the authenticity of a certificate used to encrypt the caller identification information; and comparillg the decrypted caller identification information with the caller identification information from the voice earner signal.

The present invention utilizes the principle that in telephone calls, voice and data carrier signals can be communicated simultaneously, as for instance is disclosed in h and: http:/!pocketnowcom/tech-news!simu1taneousvoice-data-coniing4ocdma.

By encrypting a caller ID at the caller's end, e.g. using a private key, including this encrypted caller ID in the digital data carrier signal, e.g. as a message, and decrypting the encrypted caller ID at thc rccipient's end, e.g. using a public key and comparing thc decrypted caller ID with the caller ID in the voice carrier signal, a recipient of a phone call can verify the identity of a caller without the caller requiring some form of subscription and authentication with a service provider, thus simplifying the authentication process without sacrificing robustness of the verification process.

The authenticity of the caller may additionally or instead be established by verifying the authenticity ofa certificate used to encrypt the caller identification information in the recipient device. This embodiment further increases the robustness of the authentication method of the present invention, as the call may be considered unauthenticated even if the caller IDs in the voice and data streams appear to match. It is noted that the verification of the authenticity of such digital certificates is well-known per se; see for instance: http:/!cn.wikipcdia.org/wiki/Chain of trust.

In a preferred embodiment, the method further comprises generating a warning message on the recipient device if the authenticity of the caller cannot be verified, e.g. in the form of an audible (warning) signal, a visual (warning) signal or as a (warning) message on a display of the recipient device to warn the user that the call cannot be trusted, which information can be aid the user in deciding whether to terminate the call. In an alternative embodiment, in a scenario where the authenticity of said certificate cannot be verified and/or where decrypted caller identification information docs not match the caller identification information in the voice carrier signal, the method may further comprise automatically terminating the call by the recipient device such that the user is not at risk of divulging sensitive information.

In an cmbodiment, the step of comparing thc dccrypted caller identification information with the caller identification information from the voice carrier signal is performed prior to the call being answered by a user of the recipient device.

In an alternative embodiment, the step of comparing the decrypted caller identification information with the caller identification information from the voice carrier signal is performed after the call being answered by a user of the recipient device.

According to anothcr aspcct of the prcscnt invention, there is providcd a computer program product comprising a computer-readable storage medium, said medium comprising computer program code for implementing the steps of an embodiment of the method of the present invention when executed on a processor of a telephony device. This inter alia has the advantage that existing telephony devices, e.g. 3G or 4G mobile phones, may be retrofitted with an embodiment of the method of the present invention.

According to yet another aspect of the present invention, there is provided a telephony device comprising a processor adapted to simultaneously transmit and/or simultaneously receive a voice carrier signal and a digital data carrier signal, wherein the processor is further adapted to perform at least one of: (a) encrypting caller identification information identifying the telephony device; and simultaneously transmitting a voice carrier signal including the unencrypted caller identification information and a digital data carrier signal including the encrypted caller identification information; and (b) verify the identity of at least an unknown caHer at thc rccipicnt dcvicc by dccrypting thc cncryptcd callcr identification information and performing at least one of verifying the authenticity ofa certificate used to encrypt the cafler identification information; and comparing the decrypted caller identification information with the caller identification information from the voice carrier signal. Such a telephony device provides a more robust protection against fraudulent telephone calls, as a secure identification of the identity of the caller can be provided and/or detected using such a telephony device.

In an embodiment, the processor is adapted to perform both steps (a) and (b).

Ill a particularly suitable embodiment, the processor is adapted to encrypt the caller ideiltification information using a private key; and/or decrypt the encrypted caller identification information using a public key.

The processor preferably is further adapted to generate a waning message on the recipient device if the authenticity of the caller cannot be verified, thereby allowing the user to decide whether to proceed with the call, e.g. by providing the user with some warning signal, or instead terminate the call.

Alternatively, the processor may be further adapted to automatically terminate a call if the decrypted caller identification information does not match the caller identification information in thc rcccivcd voice carrier signal and/or if a certificate of the encrypted caller idcntification information cannot be verified.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which: FIG. 1 depicts a flow chart of an embodiment of a method to generate a telephone call that allows the recipient of the call to verify the identity of the caller; FIG.2 depicts a flow chart of an embodiment of a method of the present invention; FIG.3 depicts a flow chart of another embodiment of a method of the present invention; and FIG.4 schematically depicts an embodiment of a telephony device according to the present invention.

DETATLED DESCRIPTION OF THE EMBODIMENTS

It should be understood that the Figures are merely schematic and are not drawn to scale, It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

In the context of the present application, where embodiments of the present invention constitute a method, it should be understood that such a method is a process for execution by a computer, i.e. is a computer-implementable method. The various steps of the method therefore reflect various parts of a computer program, e.g. various parts of one or more algorithms.

The various embodiments of the methods of the present invention may be stored in the form of computer program code on a computer program product comprising a computer-readable storage medium. The computer-readable storage medium may be any medium that can be accessed by a computer for the retrieval of digital data from said medium. Non-limiting examples of a computer-readable storage medium include a CD, DYD, flash memory card, a USB memory stick, a random access memory, a read-only memory, a computer hard disk, a storage area network, a network server, an Internet server and so on. The computer program code may be executed by at least one processor of a telephony device to implement the steps of a particular embodiment of the methods of the present invention.

FIG. 1 depicts a flow chart of an embodiment of a method 100 of the present invention for providing caller identification information in a telephone call. The method 100 starts in step 102, after which caller identification information, e.g. a caller ID such as the telephone number associated with the caller device is encrypted in any suitable manner, e.g. using a private encryption key, in step 104. The encrypted caller identification information may optionally be incorporated in a message in step 106. As it is well-known per se how to encrypt information such as the caller identification information, this will not be explained in further detail for the sake of brevity only.

Next, the telephone call is initiated in step 108, which comprises the sub-steps of generating a voice carrier signal including the caller identification information in step lOSa and generating a data carrier signal including the encrypted caller identification information in step I 08b, e.g. in the form of a message. The sub-steps 108a and 108b are typicafly performed simultaneously. The signals are transmitted to the targeted recipient device of the initiated phone call as is well-known per se. For instance, the concept of simultaneous voice and data transmission is readily available in mobile communication standards such as 30 and 40 standards as previously mentioned; see e.g. http://pocketnow.com/tech-news/simultaneous voice-data-coming-to-cdma.

Upon the call being answered, the method may continue to provide the voice carrier signal until the call is terminated as checked in step 110, after which the method ends in step 112. It is pointed out for the avoidance of doubt that the continued provision of the voice carrier signal does not imply that the caller identification information is continuously present in this signal. Typically, the caller identification information is only present in the voice carrier signal during initiation of the call, e.g. between the first and second rings, as is well-known per se.

The uncncryptcd caller identification information in the voice carrier signal and the encrypted caller identification information in the data carrier signal may be processed by a recipient device of the phone call in order to authenticate the identity of the caller. An embodiment of such an authentication method is shown in FIG. 2. The method 200 starts in step 202, after which the method proceeds to step 204 in which the telephone call initiated in accordance with the method as shown in FIG. 1 is received in step 204. To this end, the recipient telephony device should be capable of simultaneously receiving a voice carrier signal and a data carrier signal. A non-limiting example of a suitable recipient telephony device is a device compatible with 3G and/or 4G communication standards, e.g. a mobile phone, a smart phone, a tablet device and so on.

Step 204 comprises a sub-step 204a in which the recipient device receives the voice carrier signal including the caller identification information and a sub-step 204b in which the recipient device receives the data carrier signal including the encrypted caller identification information. These sub-steps are preferably performed simultaneously, as previously explained. In step 206, the recipient device extracts the encrypted caller identification information from the data carrier signal and decrypts the encrypted caller identification information, e.g. using a public key provided by the caller. Such a public key may be stored on the recipient device in any suitable manner.

Tn step 208, the decrypted caller identification information is compared with the cafler identification information from the voice carrier signal. If the caller identification information from the different signals does not match, e.g. different caller IDs are detected or no encrypted caller identification information could be found in the data canier signal, the recipient device may conclude that the identity of the caller cannot be verified, in which case the method may proceed to step 212 in which the call is automatically terminated. On the other hand, in case of matching caller identification information, the caller can be trusted, i.e. his identity has been verified, thc method may procccd to step 210 by allowing the tclcphone call to continue until the user of the recipient device terminates the call in step 212, after which the method 200 terminates ill step 214.

In an cmbodiment, steps 206 and 208 arc pcrformcd prior to the uscr answcring thc cafl, such that the call may be terminated without exposing the user to a potentially fraudulent caller.

Alternatively, steps 206 and 208 may be performed after the user has answered the call. This for instance avoids the risk of a call from a genuine caller being refused because for some reason the genuine caller is incapable of providing the correct encryption information. In this embodiment, it may also be desirable to avoid automatic termination of the call by the recipient device and instead prompt a user that no successful authentication of the caller could be achieved, in which case the user may decide to terminate the call instead. This will be explained in morc detail with the aid of FIG. 3.

Another advantageous variation to the method of FIG. 2 is that the decryption step 206 may include a verification of the authenticity of the certificate used to encrypt the caller ideiltification information in the voice carrier signal. This for instance can be used to detect if the encrypted caller identification information has been forged, thus avoiding the risk that a caller may be falsely trusted due to matching caller identification information in the voice and data carrier signals. In this embodiment, step 208 maybe omitted altogether if it is determined that the certificate used to encrypt the caller identification information in the voice canier signal cannot be verified or otherwise trusted, in which case the call may be immediately terminated in step 212 or the user alternatively maybe prompted that the identity of the caller could not be verified.

FIG. 3 depicts an embodiment of an authentication method in which the user is responsible for terminating the call upon a caller authentication failure. The method 300 comprises the same steps as the method 200 in FIG. 2, such that the steps that have already been described in the detailed description of FIG. 2 will not be described again for the sake of brevity only.

FIG. 3 differs from FIG. 2 in that in case of non-matching caller identification information as determined in step 208 (or the detection of an unverified certificate used to generate the encrypted caller identification information in the voice carrier signal in step 206 as previously explained), the method proceeds to step 302 in which the user is warned that the identity of the caller could not be authenticated.

Such a warning may be provided in any suitable form. For instance, the warning may be an audible warning signal, such as a change in ring tone prior to the user answering the call or a warning sound generated after the user has answered the call, a visual signal such as flashing light or display or a warning message on the display of the recipient device, a sensory warning signal such as a vibration pattern, and so on.

Upon being confronted with such a warning signal, the user may decide whether or not to continue with the call in step 304. The user may for instance want to continue the call because the user has reason to trust the caller anyway, e.g. because the call was expected, because the user recognizes the voice of the caller, and so on, in which case the method proceeds to step 210. Alternatively, the user may decide to terminate the call, in which case the method proceeds to step 212.

In addition to the embodiments discussed above, the method of the present invention may further comprise generating a reporting message upon a failure to authenticate the identity of a caller and automatically forwarding the waming message to a further recipient such as a regulatory body or an authority to report this failure to allow the further recipient to take appropriate actions, e.g. track down the caller for further investigation and/or prosecution, prohibit the caller from making further spoof calls, and so on. To this end, the warning message may include the various caller authentication information provided by the caller to assist the further recipient in their investigations.

At this point it is notcd that the various embodiments of the present invention arc particularly suitable for confidential communications between a service provider and a client, where the service provider is seeking to contact the client, e.g. in the case of a financial service provider wishing to qucry a particu'ar transaction of the client, c.g. a potcntiafly fraudulent transaction on a debit or credit card. Tn such a scenario, the client receiving the call from the (financial) service provider can safely provide confidential information to the employee of the service provider as the embodiments of the method of the present invention provide the client with the reassurance that the identity of the caller has been authenticated.

FIG. 4 schematically depicts a telephony device 500 adapted to implement one or more embodiments of the present invention. The telephony device 500 typically comprises at least one processor 510, a data carricr 520 including callcr idcntification information, e.g. a SIM card comprising the phone number of the telephony device 500, an antenna 530 for transmitting and/or receiving a telephone call, a microphone 540, a loud speaker 550 and a display screen 560. The telephony device 500 may of course include additional components such as a kcy pad, a LED indicator, a camcra, a scroH bafl and so on.

In an embodiment, the telephony device 500 is a caller device. In this embodiment, the processor 510 is adapted to encrypt the caller identification information from the data carrier 520 and to initiate a telephone call to a selected recipient of the call by generating a voice carrier signal including the caller identification information in unencrypted form and a data carrier signal including the caller identification information in encrypted form, e.g. comprised in a message sent through the data carrier signal. The voice carrier signal and the data carrier signal arc typically transmitted simultaneously, e.g. through antenna 530, using a suitablc communication standard. Non-limiting examples of such suitable standards are 3G and 4G. It is of course well-known per se to include caller identification information, e.g. a caller ID such as the phone number of the caller, as metadata in the voice carrier signal, such that this will not be explained in further detail for the sake of brevity. In this embodiment, the user of the telephony device 500 may use a private key to generate the encrypted caller identification information, with the recipient of the call being provided with a public key to enable the recipient to decrypt the encrypted caller identification information.

In an alternative embodiment, the telephony device 500 is the recipient device. In this embodiment, the processor 510 is adapted to simultaneously receive the voice carrier signal including the unencrypted caller identification information and the data carrier signal including the encrypted caller identification information to verify the identity of an unknown caller at the recipient device (as previously explained, verification of a known caller may be skipped). In an embodiment, the processor 510 is adapted to verify the identity of an unknown caller by decrypting the encrypted caller identification information and verifying the authenticity of a certificate used to encrypt the caller identification information. In an alternative embodiment, the processor 510 is adapted to veri1v the identity of an unknown caller by comparing the decrypted caller identification information with the caller identification information from the voice carrier signal. In yet another embodiment, the processor 510 is adapted to first verify the authenticity of a certificate used to encrypt the caller identification information, and to subsequently compare the decrypted caller identification information with the caller identification information from the voice carrier signal if the certificate has been authenticated.

In an embodiment, the processor 510 may be further adapted to automatically terminate the call if the identity of an unknown user cannot be authenticated. Alternatively, the processor 510 may be further adapted to provide a user of the telephony device with said comparison result, e.g. in the form of a warning signal to inform the user that the identity of the caller could not be authenticated. Such a warning signal may take any suitable form, e.g. a change in ring tone, a warning sound generated on the loud speaker 550, a visual waming sign such as a flashing LED, a warning message on the display 560, a vibration through the casing of the telephony device 500, and so on.

In an embodiment, the processor 510 may be adapted to verify, i.e., authenticate, the identity of the caller prior to the recipient answering the call, in which case a waming signal may be generated to discourage the user from answering the call. In an alternative embodiment, the processor 510 may be adapted to verify, i.e., authenticate, the identity of the caller after the recipient has answered the call, in which case a warning signal may be generated to encourage the user to terminate the call.

The processor 510 of the recipient telephony device 500 may further be adapted to compare the caller identification information from the voice carrier signal against a list comprising the caller identification information of users known or familiar to the recipient, e.g. an address list. In this embodiment, the processor 510 may skip the verification or authentication of the identity of the caller if it has been found that thc caller identification information from the voice carrier signal matches caller identification infbnnation in said list.

It is noted that although the telephony device 500 has been described in terms of a caller device and a recipient device, it should be understood that the telephony device 500 may be able to act as a caller device as well as a recipient device, in which case the pmcessor 510 is adapted to encrypt caller identification information as well as to authenticate the identity of the initiator of an incoming call by decrypting the encrypted caller identification information and verif'ing the certificate used to encrypt the caller identification information and/or compare the decrypted caller identification information with the caller identification information in the voice carrier signal.

The telephony device 500 may be a mobile phone, e.g. a smart phone, which may be capable of communicating in accordance with the 30 or 40 communication standards, although it should be understood that the present invention is not limited to mobile telephony only.

While particular embodiments of the present invention have been described herein for purposes of illusiration, many modifications and changes will become apparent to those skilled in the art. Accordingly, the appended claims are intended to encompass all such modifications and changes as fall within the true spirit and scope of this invention.

Claims

CLAIMSA method (100) of providing caller identification information in a telephone call, the method comprising: encrypting (104) caller identification information; initiating (108) the telephone call, said initiating comprising: providing (1 08a) a voice carrier signal including the caller identification information; and simultaneously providing (108b) a data carrier signal including the encrypted caller identification information.
2. The method (100) of claim 1, further comprising encrypting (104) thc caller identification information using a private key.
3. A method (200, 300) of authenticating the identity of a caller in a telephone call between a caller device (500) and a recipient device (500), the method comprising: receiving (204) a telephone call initiated by a caller device (500) in accordance with the method (100) of claim 1 or 2; decrypting (206) the encrypted caller identification information at the recipient device; and veri'ing the identity of at least an unknown caller at the recipient device by at least one of: verifying the authenticity of a certificate used to encrypt the caller identification information; and comparing (208) the decrypted caller identification information with the caller identification information from the voice carrier signal.
4. The method (300) of claim 3, further comprising generating (302) a warning message on the recipient device if the authenticity of the caller cannot be verified.
5. The method (200) of claim 3, further comprising further comprising automatically terminating (212) the call by the recipient device if the authenticity of the caller cannot be verified.
6. The method (200, 300) of any of claims 3-5, further comprising decrypting (206) the encrypted caller identification information using a public key.
7. The method (200, 300) of claim 6, wherein the method comprises the steps of verif'ing the authenticity ofa certificate used to encrypt the caller identification information in the recipient device prior to comparing (208) the decrypted caller identification information with the caller identification information from the voice carrier signal at the recipient device (500).
8. The method (200, 300) of any of claims 3-7, wherein the step of comparing (208) the decrypted caller identification information with the caller identification information from the voice carrier signal is performed prior to the call being answered by a user of the recipient device.
9. The method (200, 300) of any of claims 3-8, wherein the step of comparing (208) the decrypted caller identification information with the caller identification information from the voice carrier signal is performed afler the call has been answered by a user of the recipient device.
10. The method (100, 200, 300) of any of claims 1-9, wherein the encrypted caller identification information is embedded (106) in a message.
11. A computer program product comprising a computer-readable storage medium, said medium comprising computer program code for implementing the method (100, 200, 300) of any of claims 1-10 when executed on a processor of a telephony device.
12. A telephony device (500) comprising a processor (510) adapted to simultaneously transmit and/or simultaneously receive a voice carrier signal and a digital data carrier signal, wherein the processor is further adapted to perform at least one of: (a) encrypting caller identification information identifying the telephony device; and simultaneously transmitting a voice carrier signal including the uncncryptcd caller identification information and a digital data carrier signal including the encrypted caller identification information; and (b) verify the identity of at least an unknown caller at the recipient device by decrypting the encrypted caller identification information and performing at least one of: verifying the authenticity of a certificate used to encrypt the caller identification information; and S comparing the decrypted eaHer identification information with the cafler identification information from the voice carrier signal.
13. The telephony device (500) of claim 12, wherein the processor (510) is further adapted to encrypt the caller identification information using a private key.
14. The telephony device of claim 12 or 13, wherein the processor (510) is further adapted to decrypt the encrypted caller identification information using a public key.
15. The telephony device 500) of any of claims 12-14 at least adapted to perform step (b), IS wherein the processor (510) is further adapted to generate a warning message if the authenticity of the caller cannot be verified.