Public network interphone with quantum chip

Abstract

The invention relates to the technical field of wireless communication, in particular to a public network interphone with a quantum chip. According to the interphone, a master control module and a quantum security chip work cooperatively, a quantum random number generator is used for dynamically deriving a session key, and offline security distribution of a group master key is realized by encrypting a two-dimensional code; in a communication process, a system adaptively switches a voice coding mode according to a network condition, end-to-end authentication encryption is carried out on voice data by using a hardware encryption engine, and low-delay transmission is guaranteed through a network priority mark; the device establishes a complete key life cycle management mechanism, supports regular update and forward security of session keys and instant update and backward security of a group master key when members change, and ensures that all key operations are completed in a quantum chip. According to the invention, various eavesdropping and tampering attacks are effectively resisted, and safe, real-time and clear high-confidentiality voice communication in a public network environment is realized.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of wireless communication, and particularly relates to a public network intercom with a quantum chip. BACKGROUND

[0002] With the continuous evolution of mobile communication technology and the deepening of industry digital transformation, the public network intercom is widely used in the fields of public safety, emergency command and logistics scheduling due to its wide coverage and flexible networking advantages; the current technology generally adopts a software-based digital encryption and network authentication mechanism to ensure communication security; meanwhile, quantum information technology as a frontier field provides a new technical path for information security management due to its unique physical characteristics, for example, true random number generation based on a quantum random number generator and a hardware trust root constructed by using a physically unclonable function, which significantly enhances the basic security of cryptographic applications.

[0003] Under this technical fusion background, the industry is actively exploring the combination of quantum security technology and mobile communication devices in order to build a more stable communication security system in a complex public network environment; the application is developed to improve the overall security protection level of the public network intercom under the technical development trend. SUMMARY

[0004] The application aims at the problems in the background art and provides a public network intercom with a quantum chip.

[0005] The technical scheme of the application is a public network intercom with a quantum chip, and a secure communication method thereof includes the following specific implementation steps:

[0006] S1, a secure startup and initialization step, a chain trust verification from BootROM to the operating system is established through the quantum security chip to ensure the integrity and authenticity of the system firmware;

[0007] S2, a key security distribution step, bidirectional authentication of the device and the server is completed, and a group master key is generated by the quantum security chip, and offline security distribution is realized through an encrypted two-dimensional code;

[0008] S3, a real-time secure call establishment step, when the user presses the PTT key, the transmitting end derives a dynamic session key, adaptively encodes voice data, performs hardware-level authentication encryption, and transmits through priority marking;

[0009] S4, a secure receiving and playing step, the receiving end performs security verification and decryption on the data packet, counteracts network jitter, decodes and processes, and then outputs clear voice;

[0010] S5, key life cycle management step, periodically update session key to achieve forward security, and update group master key when group member changes to achieve backward security.

[0011] Preferably, the secure boot and initialization step specifically includes:

[0012] After the device is powered on, the BootROM of the master control module loads the first stage bootloader into the internal RAM and calculates its hash value;

[0013] The BootROM verifies the hash value by instructing the quantum security chip through the SPI bus, and the quantum security chip compares the device root key generated by its physically unclonable function unit with the standard hash value pre-stored in the secure storage area;

[0014] If the verification is consistent, the master control module executes the first stage bootloader, otherwise the boot process is terminated;

[0015] After the first stage bootloader obtains the execution right, it calculates and verifies the hash value of the next stage bootloader in the same way;

[0016] Finally, the integrity of the operating system kernel is verified by the verified bootloader, and the secure boot chain is completed.

[0017] Preferably, the mutual authentication in the key secure distribution step includes:

[0018] The master control module generates a temporary SM2 asymmetric key pair;

[0019] The master control module combines the temporary public key with the device unique identifier into an authentication request message, and sends it to the quantum security chip;

[0020] The quantum security chip calculates the hash value of the request message using the SM3 hash algorithm, and performs SM2 digital signature on the hash value using the device identity private key protected by the device root key;

[0021] The master control module sends the generated digital signature, device digital certificate and temporary public key to the central authentication server through an encrypted channel;

[0022] The server verifies the device digital certificate using the pre-stored root certificate, and verifies the digital signature using the public key in the certificate to complete the mutual authentication.

[0023] Preferably, the group master key offline secure distribution in the key secure distribution step includes:

[0024] At the group master device end, the quantum security chip receives the group master key generation instruction, starts the internal quantum random number generator to generate a group master key;

[0025] The quantum security chip uses a preset transmission key to encrypt the group master key through an SM4 algorithm to generate ciphertext;

[0026] The quantum security chip encodes the ciphertext and a group identifier to generate a string data packet, and the host module converts the string into a two-dimensional code graphic for display;

[0027] At the group member device end, the two-dimensional code is scanned through a camera, and the decoded string data is directly transmitted to the quantum security chip;

[0028] The quantum security chip of the member device decodes the string, decrypts the plaintext of the group master key using the same transmission key, and finally securely stores the group master key in the secure storage area inside the chip.

[0029] Preferably, the derivation of the dynamic session key in the real-time secure call establishment step includes:

[0030] When the PTT button is pressed, the host module immediately sends a session initialization instruction containing a high-precision timestamp and a group identifier to the quantum security chip;

[0031] The quantum security chip uses the securely stored group master key, the received timestamp, and an incremental sequence number as input to determine the dynamic session key used in this session through SM3 hash operation;

[0032] The derived session key is temporarily stored in the volatile key register of the quantum security chip, and its life cycle is strictly bound to the PTT button state of this session.

[0033] Preferably, the adaptive encoded voice data in the real-time secure call establishment step includes:

[0034] A high-priority real-time audio task thread is started to collect voice data through an audio codec at a specific sampling rate and precision;

[0035] The collected data is preprocessed by a digital filter chain, sent to a buffer, and submitted to the host module in fixed time length frames;

[0036] At the same time, an independent network monitoring thread continuously evaluates the channel quality, including received signal strength, packet error rate, and round-trip delay;

[0037] Based on the channel quality evaluation results, the system seamlessly switches between a high-quality mode and a robust mode; the high-quality mode uses a wideband audio encoder, and the robust mode uses a narrowband audio encoder and enables discontinuous transmission function.

[0038] Preferably, the real-time secure call establishment step includes the following steps:

[0039] The host module combines each frame of encoded voice data with a frame header into a plaintext data block, and sends the plaintext data block into the quantum security chip through the SPI bus;

[0040] The quantum security chip uses the dynamic session key to process the plaintext data block in an SM4-GCM authentication encryption mode, to generate a ciphertext and a corresponding authentication tag;

[0041] The host module encapsulates the ciphertext, the authentication tag, and a communication protocol header into a network data packet;

[0042] Before sending the network data packet, the system call is used to set the IP service type field of the network data packet to a differentiated service code point value representing accelerated forwarding, to instruct the communication module and the network device to perform priority transmission on the network data packet.

[0043] Preferably, the secure receiving and playing step includes the following steps:

[0044] Security verification and decryption: the host module of the receiving end analyzes the received network data packet, separates the encrypted voice payload, the authentication tag, and the group identifier, and sends them into the quantum security chip for decryption and verification; if the verification fails, the network data packet is discarded; if the verification succeeds, the decrypted voice encoding data is output;

[0045] Anti-network jitter processing: the successfully decrypted voice frame is sent into an adaptive jitter buffer with a depth that can be adjusted, and the depth of the adaptive jitter buffer is dynamically adjusted according to the time interval of packet arrival; when a discontinuous sequence number is detected, a packet loss concealment algorithm is started;

[0046] Intelligent decoding and audio post-processing: the host module dynamically calls a corresponding decoder according to the encoding type identifier in the decrypted data, to restore the compressed data into a linear pulse code modulation audio stream; the audio stream is sequentially subjected to dynamic range compression, automatic gain control, and high-frequency enhancement processing;

[0047] The processed audio data is converted into an analog signal by an audio codec, to drive a loudspeaker to play out the analog signal.

[0048] Preferably, the key lifecycle management step includes the following steps:

[0049] Periodic session key update: a security timer built in the host module sends a key update instruction to the quantum security chip at a predetermined period; the quantum security chip derives a new dynamic session key based on the current group master key and a new timestamp, and the new dynamic session key takes effect immediately, while the old session key is completely cleared; the receiving end synchronously completes the key switching through a signaling channel;

[0050] Event-driven group master key update, when the group member is removed, the quantum security chip of the group master device generates a new group master key; the group master device constructs a re-key signaling packet using the original group master key to encrypt the new group master key, and uses the quantum security chip of the group master device to digitally sign the signaling packet; the server broadcasts the signed signaling packet, and the legitimate members verify the signature and decrypt to complete the key update, and the removed members cannot complete the process.

[0051] Preferably, the system architecture comprises:

[0052] The master control module adopts a dual-core application processor and runs a trimmed Linux operating system, wherein one core is dedicated to real-time voice codec and network scheduling, and the other core processes human-computer interaction and background tasks;

[0053] The quantum security chip is connected with the master control module through an SPI bus, and the chip is integrated with a quantum random number generator based on CMOS photon noise, a physically unclonable function unit for generating a device unique root key, a hardware accelerated national secret algorithm engine and a physical anti-disassembly mechanism;

[0054] The communication module adopts a mobile communication module supporting quality of service and differentiated service code point marking functions;

[0055] The audio module contains a high-performance codec and is connected with the master control module through an I2S bus.

[0056] Compared with the prior art, the above technical scheme of the present application has the following beneficial technical effects:

[0057] The application designs a public network intercom with a quantum chip, constructs a secure boot system based on a hardware root of trust by introducing a quantum security chip, ensures the integrity and authenticity of the device firmware, generates a device unique root key by using the physically unclonable function integrated in the chip, and generates key materials with true randomness by combining a quantum random number generator, realizes offline secure distribution of group master keys and real-time derivation of dynamic session keys, and alleviates the risk of key prediction or theft in the generation and distribution link; in the communication process, the system uses the national encryption algorithm to perform end-to-end hardware-level authentication encryption on the voice data, and intelligently switches the voice coding mode and adjusts the network transmission priority according to the real-time network condition, so that the dual goals of high-level security and privacy and low-delay high-quality voice communication are achieved simultaneously in a complex public network environment; the application further establishes a perfect key life cycle management mechanism, guarantees the forward security of communication by periodically updating the session key, and immediately updates the group master key when the group members change to realize backward security, all key security operations are strictly limited to be completed in the chip internal secure environment, forming a closed-loop security ecology, which can effectively resist various threats such as man-in-the-middle attack, replay attack and physical tampering, and finally provides the user with high communication security protection and reliable practical experience which the traditional intercom does not have. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 The application provides a work flow chart of the public network intercom with the quantum chip. DETAILED DESCRIPTION

[0059] In embodiment one, the application provides a public network intercom with a quantum chip, which comprises a main control module, a quantum security chip, a communication module and an audio module.

[0060] The main control module adopts a dual-core ARM Cortex-A7 (for example, NXP i.MX6UL series) as an application processor, and runs a Linux operating system after being trimmed; one core is dedicated to real-time voice coding and decoding and network scheduling, and the other core processes human-computer interaction (UI) and background tasks, so as to ensure low delay of voice processing;

[0061] The quantum security chip (QSC) is connected with the main control module through an SPI bus, and the chip integrates: a quantum random number generator based on CMOS photon noise, which is used to generate a true random number; an SRAM physically unclonable function unit, which is used to generate a device unique root key; a hardware-accelerated national encryption algorithm engine, which supports SM2, SM3 and SM4 algorithms; and a physical anti-disassembly probe mechanism, which automatically clears the key storage after being triggered;

[0062] The communication module adopts a 4G / 5G communication module, and supports QoS and DSCP marking functions;

[0063] The audio module comprises a high-performance codec and is connected with the host module through an I2S bus.

[0064] In the second embodiment, the application provides a public network intercom with a quantum chip, as shown in the figure, and the working process is as follows: Figure 1

[0065] S1, by establishing a chain trust verification mechanism from BootROM to the operating system, the quantum security chip generates a device root key by using a physically unclonable function, verifies the digital signature of each stage of the boot program step by step, ensures the integrity and authenticity of the system firmware, and any verification failure will immediately terminate the starting process, and the specific process is as follows:

[0066] S11, first, the device is powered on, and the solidified code in the read-only memory (BootROM) of the host module is first run; the BootROM code loads the first stage boot loader (SPL) stored in the external nonvolatile memory (such as eMMC) into the internal RAM, and calculates the password hash value (such as SM3 hash);

[0067] S12, the BootROM code instructs the quantum security chip (QSC) to verify the hash value through the SPI bus, the QSC receives the verification request, activates the physically unclonable function (PUF) module, and uses the device root key generated by the module, which is unique and unclonable, to compare the signed standard SPL hash value pre-stored in the QSC secure storage area;

[0068] If the hash values are consistent, the verification is passed, and the host module starts to execute the SPL; if the verification fails, the QSC will return an error signal to the host module, and the system starting process is terminated, and the device enters a safe locking state;

[0069] S13, after the SPL obtains the execution right, the trust chain is inherited, and the integrity and authenticity of the next stage boot program (such as U-Boot) are verified in the same way: the hash value of the U-Boot image is calculated by the SPL and sent to the QSC for verification;

[0070] S14, the verified U-Boot is responsible for verifying the final operating system (such as Linux) kernel;

[0071] Accordingly: the complete security starting chain from BootROM to the operating system kernel is established, the system control right is transferred to the operating system, and the initialization process is completed.

[0072] ​S2, the device generates a digital certificate with the quantum security chip and completes mutual authentication with the server, and the group master key is generated by a quantum random number generator in the chip and is distributed offline securely through an encrypted two-dimensional code to ensure that the key is not leaked during transmission, thereby establishing a basic key system for group communication, specifically:

[0073] S21, performing device identity authentication and network registration procedures, specifically:

[0074] The device authentication step establishes mutual trust between the device and the network server; the master module first generates a temporary SM2 asymmetric key pair (public key PK_temp and private key SK_temp), which is only used for this registration session;

[0075] The master module combines PK_temp and the device's unique identifier DEVICE_ID into an authentication request message and sends it to the quantum security chip (QSC) for signature;

[0076] After receiving the request, the QSC performs the following security operations:

[0077] The SM3 hash algorithm is called to calculate the hash value H1 of the request message;

[0078] The device identity private key SK_device protected by the PU F root key is used to sign H1 through the SM2 digital signature algorithm to generate a digital signature SIG_device;

[0079] SIG_device, the device digital certificate CERT_device (which contains the device permanent public key PK_device), and PK_temp are returned to the master module;

[0080] The master module constructs a complete registration request data packet and sends it to the central authentication server through a strictly configured TLS1.3 encryption channel (using the TLS_AES_256_GCM_SHA384 cipher suite);

[0081] After the server receives the request, it performs a verification chain:

[0082] First, the validity and authenticity of CERT_device are verified using the pre-installed root certificate;

[0083] After verification, the PK_device in CERT_device is used to verify the signature SIG_device to confirm that the request message has not been tampered with during transmission and indeed comes from a trusted device;

[0084] After all the verifications pass, the server records the PK_temp binding with the device, and sends a registration success confirmation message to the device, completing the device network access authentication;

[0085] S22, a security distribution and establishment procedure of the group master key is executed, specifically:

[0086] The distribution of the group master key adopts an offline and visual two-dimensional code mechanism, ensuring that the key does not contact any network channel in the distribution process, and eliminating man-in-the-middle attacks and network eavesdropping;

[0087] A1, at the group master device end, the specific implementation process is as follows:

[0088] After the user selects to create a group on the operation interface, the master control module sends a GEN_GMK instruction to the QSC;

[0089] After the QSC receives the instruction, the internal quantum random number generator (QRNG) module of the QSC is started, and a 256-bit group master key (GMK) with complete randomness is generated based on photon noise sampling; the plaintext of the GMK is always securely isolated in the hardware security area of the QSC;

[0090] The QSC uses the preset transmission key K_trans (or a key derived from the group master device root key) agreed by all group members to encrypt the GMK using the SM4 algorithm (GCM mode) to generate the ciphertext C_GMK;

[0091] In order to facilitate offline transmission, the QSC encodes the C_GMK and the group identifier GROUP_ID together using Base64, and finally generates a string data packet;

[0092] The master control module converts the string into a two-dimensional code pattern and presents it on the display screen;

[0093] A2, at the group member device end, the execution process is as follows:

[0094] The new member scans the two-dimensional code displayed by the group master device through the camera of the device;

[0095] After successful scanning, the obtained Base64 string is directly transmitted to the QSC chip of the member device;

[0096] The QSC first performs Base64 decoding on the string to separate the C_GMK and the GROUP_ID;

[0097] The same transmission key K_trans (or the decryption key obtained by verifying the group master signature) is used to perform SM4 decryption on the C_GMK to restore the plaintext of the GMK;

[0098] The QSC of the member device binds the decrypted GMK with the GROUP ID and securely stores it in a secure storage area inside the chip; before storage, the QSC can optionally perform secondary encryption on the GMK using a key derived from the device root key to provide an additional layer of storage security;

[0099] After successful storage, the member device returns a success status to the master module, and at this point, the member has securely obtained the group master key;

[0100] Accordingly, all legitimate members in the group can securely share the same GMK after being completely offline or through one-time encrypted online interaction, providing a reliable security foundation for the dynamic key derivation of each subsequent call session, while effectively avoiding various network attacks that the key may encounter during distribution.

[0101] S3, when the user presses the PTT (push-to-talk) to initiate a session, the transmitting intercom starts a highly integrated real-time processing flow, which includes four technical stages: dynamic session key derivation, adaptive voice acquisition and coding, hardware encryption packaging, and network priority transmission, specifically:

[0102] S31, the moment the PTT key is detected, the master module immediately sends a SESSION_INIT instruction containing the current high-precision timestamp (precision 1 ms) and group ID to the quantum security chip (QSC);

[0103] After the QSC receives the instruction, it performs the following deterministic algorithm to derive the session key (SK) inside the chip: SK = SM3_HASH(GMK||Timestamp||Sequence_Number);

[0104] Where GMK is the pre-stored group master key; Sequence_Number is a counter that increments with each key press to prevent replay attacks; Timestamp is the timestamp; and SM3_HASH() is the SM3 encryption algorithm;

[0105] The derived 256-bit SK is temporarily stored in the volatile key register of the QSC, and its life cycle is strictly bound to the PTT key state;

[0106] S32, the system starts a high-priority real-time audio task thread:

[0107] It is collected by the audio Codec (such as TLV320AIC3106) at a sampling rate of 16 kHz and a precision of 16 bits in stereo sound, and then preprocessed by a high-efficiency digital filter chain (including high-pass filtering to remove DC and noise suppression);

[0108] The processed audio data is sent into a ping-pong buffer, and the dedicated DMA controller automatically submits an interrupt to the main control module in 20ms increments (i.e., 320 sampling points per frame);

[0109] An independent network monitoring thread is constructed to continuously evaluate channel quality and maintain a state vector containing Received Signal Strength Indicator (RSSI), Packet Error Rate (PER), and Round-Trip Time (RTT). Based on this vector, the system seamlessly switches between the following two coding modes:

[0110] Premium Mode (RSSI>-85dBm & PER<2%): Activates the Opus encoder, configured as MODE_SILK, with a target bitrate of 24kbps, providing wideband audio from 50Hz to 7kHz;

[0111] Robust Mode (Trigger Switching): Immediately switches to the ARM-NB encoder at a bitrate of 12.2kbps, and simultaneously enables its built-in SID (Silence Indicator Frame) and DTX (Discontinuous Transmission) functions to further save bandwidth and power consumption.

[0112] S33. Each frame of encoded voice data (approximately 40-60 bytes) is combined with the keyframe header (frame sequence number, encoding type identifier) ​​into a plaintext data block P; the main control module sends P to the QSC via the SPI bus and sends ENCRYPT_CMD; the QSC executes:

[0113] Use SK to process P in SM4-GCM certified encryption mode;

[0114] Generate ciphertext C and a 128-bit GCM authentication tag;

[0115] This Auth tag serves as strong proof of data integrity and authenticity and is output along with the ciphertext C;

[0116] S34. The main control module encapsulates the ciphertext C, the Auth Tag, and the necessary communication protocol headers (such as RTP / UDP headers) into a data packet;

[0117] Before calling the Socket send interface, the IP TOS field of the data packet is set to the DSCP EF(101110) value via the setsockopt() system call; this operation instructs all routing devices in the underlying 4G / 5G module and network to put this data packet into the highest priority forwarding queue.

[0118] Therefore, this high-priority, end-to-end encrypted voice data packet is efficiently sent to the target recipient over the public network.

[0119] S4, the receiving end intercom performs a security processing pipeline strictly corresponding to the transmitting end, realizing low-delay and high-fidelity restoration from encrypted data packets to clear voice, which includes four key stages: security verification and decryption, anti-network jitter processing, intelligent decoding and audio post-processing, specifically:

[0120] S41, after the receiving end communication module captures the UDP data packets transmitted through the 4G / 5G network, the network protocol stack of the host module immediately analyzes and separates the following key components: encrypted voice load (Ciphertext), 128-bit GCM authentication tag (Auth Tag), RTP header information (including frame sequence number and timestamp), group identifier (Group ID);

[0121] The host module sends the encrypted data and authentication tag to the quantum security chip (QSC) through the high-speed SPI bus and issues a DECRYPT_VERIFY_CMD instruction; QSC uses the dynamic session key (SK) synchronized with the transmitting end to perform SM4-GCM algorithm for decryption and authentication;

[0122] If the authentication fails, QSC immediately returns a specific error code (such as AUTH_FAILURE), and the host module discards the data packet, records this security event in the system log, and optionally triggers a slight packet loss prompt tone;

[0123] If the authentication is successful, QSC outputs the decrypted original voice encoding data (such as Opus or ARM-NB format) and complete frame header information;

[0124] S42, the successfully decrypted voice frames are sent to a dynamically deep adaptive jitter buffer; the buffer is driven by an intelligent algorithm, continuously monitoring the arrival time interval and sequence number continuity of the last N data packets; its depth dynamically adjusts between 20ms and 80ms:

[0125] When the network is stable, maintain the minimum depth (20ms) to reduce the delay;

[0126] When detecting that network jitter intensifies (the increase of packet arrival time variation), automatically increase the buffer depth (up to 80ms) to smooth the playback;

[0127] When detecting packet loss (sequence number discontinuity), start the forward error correction (FEC) mechanism (if enabled during encoding) or the packet loss concealment (PLC) algorithm, intelligently generate replacement data through the audio information of the previous and subsequent frames, instead of producing harsh silence;

[0128] S43, the master module dynamically calls the corresponding decoder instance according to the Codec Type field identified by the decrypted data frame header:

[0129] If identified as 0x01, call the Opus decoder and configure it in the mode corresponding to the transmitting end;

[0130] If identified as 0x02, call the ARM-NB decoder;

[0131] The decoding process restores the compressed voice data to a 16kHz sampling rate, 16-bit linear PCM audio stream; then, the PCM data stream passes through an audio post-processing module, which performs the following functions in sequence:

[0132] Dynamic range compression (DRC): automatically adjust the volume to avoid large and small sounds;

[0133] Automatic gain control (AGC): ensures that the playback volume is stable at a comfortable level;

[0134] High frequency enhancement: compensates for high frequency loss caused by narrowband coding and improves voice clarity;

[0135] S44, the processed final PCM data is transmitted to the audio codec (Codec) in a double-buffering (Double-Buffering) manner through the I2S bus;

[0136] The DAC module of the Codec converts digital signals to analog signals, which are driven by a low-noise AB class or higher-efficiency D class power amplifier to drive the loudspeaker;

[0137] The entire receiving and processing link, from the arrival of the data packet to the sound playback, has an end-to-end delay strictly optimized and controlled within 100 milliseconds, ensuring smooth and natural communication between the two parties.

[0138] S5, establish a key lifecycle management system, regularly update the session key to ensure forward security, and immediately update the group master key when the group members change to achieve backward security. All key update operations are completed within the quantum security chip, and the legality of the update instruction is verified through digital signature, building a complete key security ecosystem, that is, the system implements a strict key lifecycle management mechanism, including periodic session key update and event-driven group master key update, specifically:

[0139] S51, during a single long call, the system implements key rolling update with forward security as the goal;

[0140] The master module has a built-in security timer that sends key update instructions to the quantum security chip (QSC) every 300 seconds by default;

[0141] After receiving the instruction, the QSC derives a new dynamic session key (New SK) based on the current group master key (GMK) and the new timestamp through SM3 hash operation;

[0142] The new key takes effect immediately for subsequent data encryption, and all storage traces of the previous session key are completely cleared;

[0143] The receiving end synchronously completes the switching of the local session key by analyzing the key update instruction in the signaling channel;

[0144] When the group members change, the system starts a group master key (GMK) update process to ensure backward security;

[0145] After detecting the member removal event, the group master device generates a new group master key (New GMK) using an internal quantum random number generator (QRNG);

[0146] The group master device constructs a secure re-key signaling packet, which contains the New GMK encrypted with the original GMK and is signed with the group master device's QSC using SM2 digital signature;

[0147] The server broadcasts this signed re-key signaling packet to the current list of legitimate member devices; after receiving the signaling packet, each member device first verifies the validity of the SM2 signature to confirm the credibility of the instruction source; after verification, the New GMK is obtained by decrypting the stored original GMK, and the key replacement is immediately completed in the QSC's secure storage area; the removed member device is permanently excluded from subsequent group communication due to the inability to pass the signature verification or decrypt the new key;

[0148] It should be noted that all key update operations are completed in the QSC hardware security environment, ensuring that the key material is not exposed in plaintext form outside the chip at any time, thereby building a complete key security management system.

[0149] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited thereto, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the purpose of the application.

Claims

1. A public intercom having a quantum chip, characterized by, The secure communication method comprises the following specific implementation steps: S1, a secure start and initialization step, a chain trust verification from BootROM to an operating system is established through a quantum security chip to ensure the integrity and authenticity of system firmware; S2, a key security distribution step, two-way authentication of a device and a server is completed, and a group master key is generated by the quantum security chip, and offline security distribution is realized through an encrypted two-dimensional code; S3, a real-time secure call establishment step, when a user presses a PTT button, a dynamic session key is derived, adaptive coded voice data is transmitted, hardware level authentication encryption is performed, and transmission is performed through a priority marker; S4, a secure receiving and playing step, the receiving end performs security verification and decryption on the data packet, counteracts network jitter, decodes and processes, and then outputs clear voice; S5, a key life cycle management step, the session key is updated regularly to realize forward security, and the group master key is updated when the group members change to realize backward security.

2. A public intercom with a quantum chip according to claim 1, characterized in that, The secure start and initialization step specifically comprises: After the device is powered on, the BootROM of the host module loads the first stage bootloader to the internal RAM and calculates the hash value thereof; The BootROM verifies the hash value through the SPI bus instruction quantum security chip, and the quantum security chip compares the device root key generated by the physically unclonable function unit with the standard hash value pre-stored in the secure storage area; If the verification is consistent, the host module executes the first stage bootloader, otherwise the startup process is terminated; After the first stage bootloader obtains the execution right, the hash value of the next stage bootloader is calculated and verified in the same way; Finally, the integrity of the operating system kernel is verified by the verified bootloader, and the secure start chain is completed.

3. A public intercom with a quantum chip according to claim 2, characterized in that, The two-way authentication in the key security distribution step comprises: The host module generates a temporary SM2 asymmetric key pair; The host module combines the temporary public key and the device unique identifier into an authentication request message, and sends it to the quantum security chip; The quantum security chip calculates the hash value of the request message using the SM3 hash algorithm, and performs SM2 digital signature on the hash value using the device identity private key protected by the device root key; The host module sends the generated digital signature, device digital certificate and temporary public key to the central authentication server through an encrypted channel; The server verifies the device digital certificate using the pre-stored root certificate, and verifies the digital signature using the public key in the certificate to complete the two-way authentication.

4. A public intercom with a quantum chip according to claim 3, characterized in that, The group master key offline security distribution in the key security distribution step comprises: At the group master device end, the quantum security chip receives the group master key generation instruction, starts the internal quantum random number generator to generate a group master key; The quantum security chip encrypts the group master key through the SM4 algorithm to generate ciphertext using the pre-stored transmission key; The quantum security chip encodes the ciphertext and the group identifier to generate a string data packet, and the host module converts the string into a two-dimensional code pattern for display; At the group member device end, the two-dimensional code is scanned through the camera, and the decoded string data is directly transmitted to the quantum security chip; The quantum security chip of the member device decodes the string and decrypts the plaintext of the group master key using the same transmission key, and finally securely stores the group master key in the secure storage area inside the chip.

5. A public intercom with a quantum chip according to claim 4, characterized in that, Derivation of the dynamic session key in the real-time secure call establishment step includes: When the PTT button is pressed, the host module immediately sends a session initialization instruction containing a high-precision timestamp and a group identifier to the quantum security chip; The quantum security chip uses the securely stored group master key, the received timestamp, and an incrementing sequence number as input to deterministically derive the dynamic session key for this session through SM3 hash operation; The derived session key is temporarily stored in the volatile key register of the quantum security chip, and its lifetime is strictly bound to the PTT button state of this session.

6. A public intercom with a quantum chip according to claim 5, characterized in that, Adaptive coding of voice data in the real-time secure call establishment step includes: Start a high-priority real-time audio task thread to collect voice data at a specific sampling rate and precision through an audio codec; The collected data is preprocessed by a digital filter chain, then sent to the buffer and submitted to the host module in fixed time length frames; At the same time, an independent network monitoring thread continuously evaluates channel quality, including received signal strength, packet error rate, and round-trip delay; Based on the channel quality evaluation results, the system seamlessly switches between high-quality mode and robust mode; the high-quality mode uses a wideband audio encoder, and the robust mode uses a narrowband audio encoder and enables discontinuous transmission.

7. A public intercom with a quantum chip according to claim 6, characterized in that, Hardware-level authentication encryption and priority marking transmission in the real-time secure call establishment step include: The host module combines each frame of encoded voice data with a frame header into a plaintext data block, which is sent to the quantum security chip through the SPI bus; The quantum security chip uses the dynamic session key to process the plaintext data block using the SM4-GCM authentication encryption mode to generate ciphertext and the corresponding authentication tag; The host module encapsulates the ciphertext, authentication tag, and communication protocol header into a network data packet; Before sending the data packet, set the IP service type field of the data packet to the differentiated service code point value representing accelerated forwarding through a system call to instruct the communication module and network device to transmit it preferentially.

8. A public intercom with a quantum chip according to claim 7, characterized in that, The secure reception and playback step includes: Security verification and decryption: the host module of the receiving end parses the received data packet, separates the encrypted voice payload, authentication tag, and group identifier, and sends them to the quantum security chip for decryption and verification; if the authentication fails, the data packet is discarded, and if it is successful, the decrypted voice encoding data is output; Anti-network jitter processing: the successfully decrypted voice frames are sent to an adaptive jitter buffer with adjustable depth, and the buffer depth is dynamically adjusted according to the packet arrival time interval, and the packet loss concealment algorithm is started when a discontinuous sequence number is detected; Intelligent decoding and audio post-processing: the host module dynamically calls the corresponding decoder according to the encoding type identifier in the decrypted data to restore the compressed data to a linear pulse code modulation audio stream; the audio stream is processed in turn through dynamic range compression, automatic gain control, and high-frequency enhancement. The processed audio data is converted into an analog signal by an audio codec to drive a loudspeaker to play out.

9. A public intercom with a quantum chip according to claim 8, characterized in that, The key life cycle management step comprises: Periodic session key update, the security timer in the master module sends key update instruction to the quantum security chip at a predetermined period; the quantum security chip derives a new dynamic session key based on the current group master key and the new timestamp and takes effect immediately, while completely clearing the old session key; the receiving end completes the key switching through the signaling channel synchronously; Event-driven group master key update, when a group member is removed, the quantum security chip of the group master device generates a new group master key; the group master device constructs a re-key signaling packet using the original group master key to encrypt the new group master key, and uses the quantum security chip of the group master device to digitally sign the signaling packet; the server broadcasts the signed signaling packet, and the legitimate members verify the signature and decrypt to complete the key update, and the removed members cannot complete the process.

10. A public intercom with quantum chip according to any one of claims 1-9, characterized in that, The system architecture comprises: The master module adopts a dual-core application processor, and runs a trimmed Linux operating system, one core of which is dedicated to real-time voice codec and network scheduling, and the other core processes human-computer interaction and background tasks; The quantum security chip is connected with the master module through an SPI bus, the chip integrates a quantum random number generator based on CMOS photon noise, a physical unclonable function unit for generating a device unique root key, a hardware accelerated national secret algorithm engine, and a physical anti-disassembly mechanism; The communication module adopts a mobile communication module supporting quality of service and differentiated services code point marking function; The audio module contains a high-performance codec connected with the master module through an I2S bus.

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