System, method, and apparatus for detecting call interception

1 . An apparatus comprising at least one processor and at least one non-transitory memory including computer program code instructions, the computer program code instructions configured to, when executed, cause the apparatus to at least:

establish a shared resource for a session with a remote end device;

select a nonce and provide the nonce to the remote end device to establish a shared secret with the remote end device;

generate a sequence of bits;

divide the sequence of bits into a predetermined number of sub-sequences;

perform a bit exchange with the remote end device using dual tone multi-frequency (DTMF) tones to send each sub-sequence of the predetermined number of sub-sequences to the remote end device;

receive a DTMF response and determine a transmission time;

decode and reconcile the DTMF response;

determine, from the bit exchange, an average time of transmission; and

identify a presence of an adversary intercepting the session in response to the average time of transmission exceeding a predetermined time.

2 . The apparatus of claim 1 , wherein causing the apparatus to perform a bit exchange with the remote end device using DTMF further comprises causing the apparatus to determine a time of transmission for each bit exchange with the remote end device.

3 . The apparatus of claim 2 , wherein the average time of transmission comprises an average of the time of transmission for each bit exchange with the remote end device.

4 . The apparatus of claim 1 , wherein causing the apparatus to identify the presence or absence of an adversary intercepting the session comprises causing the apparatus to determine the presence of an adversary intercepting the session in response to the average time of transmission being above a first predetermined value.

5 . The apparatus of claim 4 , wherein causing the apparatus to identify the presence or absence of an adversary intercepting the session comprises causing the apparatus to determine the absence of an adversary intercepting the session in response to the average time of transmission being below a second predetermined value.

6 . The apparatus of claim 1 , wherein the sequence of bits is based on a number of challenges to the remote end device and a number of bits in each of the challenges to the remote end device.

7 . The apparatus of claim 1 , wherein causing the apparatus to establish the shared resource comprises causing the apparatus to generate the shared resource using transport layer security (TLS).

8 . A computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising program code instructions to:

establish a shared resource for a session with a remote end device;

select a nonce and provide the nonce to the remote end device to establish a shared secret with the remote end device;

generate a sequence of bits;

divide the sequence of bits into a predetermined number of sub-sequences;

perform a bit exchange with the remote end device using dual tone multi-frequency (DTMF) tones to send each sub-sequence of the predetermined number of sub-sequences to the remote end device;

receive a DTMF response and determine a transmission time;

decode and reconcile the DTMF response;

determine, from the bit exchange, an average time of transmission; and

identify a presence of an adversary intercepting the session in response to the average time of transmission exceeding a predetermined time.

9 . The computer program product of claim 8 , wherein the program code instructions to perform a bit exchange with the remote end device using DTMF further comprise program code instructions to determine a time of transmission for each bit exchange with the remote end device.

10 . The computer program product of claim 9 , wherein the average time of transmission comprises an average of the time of transmission for each bit exchange with the remote end device.

11 . The computer program product of claim 8 , wherein the program code instructions to identify the presence or absence of an adversary intercepting the session comprise program code instructions to determine the presence of an adversary intercepting the session in response to the average time of transmission being above a first predetermined value.

12 . The computer program product of claim 11 , wherein the program code instructions to identify the presence or absence of an adversary intercepting the session comprise program code instructions to determine the absence of an adversary intercepting the session in response to the average time of transmission being below a second predetermined value.

13 . The computer program product of claim 8 , wherein the sequence of bits is based, at least in part, on a number of challenges to the remote end device and a number of bits in each of the challenges to the remote end device.

14 . The computer program product of claim 8 , wherein the program code instructions to establish the shared resource comprise program code instructions to generate the shared resource using transport layer security (TLS).

15 . A method comprising:

establishing a shared resource for a session with a remote end device;

selecting a nonce and provide the nonce to the remote end device to establish a shared secret with the remote end device;

generating a sequence of bits;

dividing the sequence of bits into a predetermined number of sub-sequences;

performing a bit exchange with the remote end device using dual tone multi-frequency (DTMF) tones to send each sub-sequence of the predetermined number of sub-sequences to the remote end device;

receiving a DTMF response and determine a transmission time;

decoding and reconcile the DTMF response;

determining, from the bit exchange, an average time of transmission; and

identifying a presence of an adversary intercepting the session in response to the average time of transmission exceeding a predetermined time.

16 . The method of claim 15 , wherein performing a bit exchange with the remote end device using DTMF further comprises determining a time of transmission for each bit exchange with the remote end device.

17 . The method of claim 16 , wherein the average time of transmission comprises an average of the time of transmission for each bit exchange with the remote end device.

18 . The method of claim 15 , wherein identifying the presence or absence of an adversary intercepting the session comprises determining the presence of an adversary intercepting the session in response to the average time of transmission being above a first predetermined value.

19 . The method of claim 18 , wherein identifying the presence or absence of an adversary intercepting the session comprises determining the absence of an adversary intercepting the session in response to the average time of transmission being below a second predetermined value.

20 . The method of claim 15 , wherein the sequence of bits is based, at least in part, on a number of challenges to the remote end device and a number of bits in each of the challenges to the remote end device.