Data Processing System

Abstract

A system for data processing using multi-party operations based on homomorphic encryption is proposed, wherein the system comprises a plurality of data processing devices, and each of the plurality of data processing devices may be configured to include: a transceiver configured to provide communication with other data processing devices; a memory configured to store code for performing operations for data processing using multi-party operations based on homomorphic encryption; and a processor that supports execution in a Trusted Execution Environment (TEE) region for executing said code.

Description

Technology Field

[0001] The present invention relates to a data processing system and a device included therein, and more specifically, to a system for data processing using homomorphic encryption-based multi-party operations and a data processing device included therein, and relates to a technology in which a plurality of data processing devices perform homomorphic encryption-based multi-party operations. Background Technology

[0002] Multi-party Computation (MPC) technology is a security protocol that derives a result by enabling different data owners to collaborate on common operations requiring each other's data as input, without disclosing their data to one another. Multi-party computation is used in various application fields, such as statistics, machine learning, and inference.

[0003] FIG. 1 is a diagram briefly illustrating a multi-party operation. Referring to FIG. 1, a multi-party operation is described for calculating the total sum and average of the bank account balances of three users without disclosing their bank account balances to each other.

[0004] Assume that User 1 has a bank account balance of $200, User 2 has a bank account balance of $300, and User 3 has a bank account balance of $400. Previously, to calculate the total sum and average of the three users' bank account balances without multi-party computation, each user's bank account balance had to be shared with one another. However, in multi-party computation, each user can divide their balance into three parts, keeping one part for themselves and transferring the remaining parts to other users, thereby keeping their balance private. The three parts into which each user divides their balance can be referred to as "secret shares." Each user can perform a summation operation on their secret shares and the secret shares of other users, and share the results with other users. Accordingly, as illustrated, a total sum of $600 and an average of $200 can be obtained, while the bank account balances of other users remain unknown, thus maintaining data security.

[0005] Meanwhile, the biggest challenge in the practical application of multi-party computation technology is communication overload. This is because in multi-party computation, all operations must be converted into the form of addition and multiplication, and each multiplication requires a round trip time (RTT) between protocol participants. Fully homomorphic encryption technology has emerged as an alternative to the communication overload problem of multi-party computation; this is an encryption technique that enables unlimited addition and multiplication operations while the data remains encrypted. Figure 2 illustrates the structure of homomorphic encryption technology. The customer side encrypts the data with a homomorphic encryption key and transmits it to the cloud side, and the cloud side performs homomorphic operations on the encrypted data and transmits it back to the customer.

[0006] However, one of the problems with homomorphic encryption technology is that the data used in homomorphic operations must be encrypted with the same homomorphic key. Therefore, when the data originates from different sources, a key-switching key must be used to make the different keys identical for homomorphic operations; this presents a security issue in that the entity generating this key-switching key can become a single-point failure. While key-switching keys can be managed within a Trusted Execution Environment (TEE), TEEs are vulnerable to various side-channel attacks.

[0007] To address the aforementioned issues, this proposal suggests a secure and communication-efficient protocol through multi-party TEE-based homomorphic key generation and management. Unlike existing multi-party computation-based protocols, this protocol ensures that communication volume is not affected by the complexity of the target computation expression. Consequently, it achieves high computational communication efficiency while simultaneously securing an equivalent security objective of not directly exposing any intermediate values ​​to participants other than the computation result. The problem to be solved

[0008] The present invention proposes a system for data processing using multi-party operations based on homomorphic encryption and a data processing device included therein.

[0009] The problems to be solved by the present invention are not limited to the problems to be solved above, and other problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0010] According to one embodiment of the present invention, a system for data processing is proposed, wherein the system comprises a plurality of data processing devices configured to perform data processing using a multi-party operation based on homomorphic encryption, and each of the plurality of data processing devices may include: a transceiver configured to provide communication with other data processing devices; a memory configured to store code for performing an operation for data processing using the multi-party operation based on homomorphic encryption; and a processor that supports execution in a Trusted Execution Environment (TEE) area for executing the code, and the memory may be configured to include a first area configured to store data requiring the multi-party operation and a second area configured to store or install the TEE. Additionally, the above operation may include the processor obtaining a piece of a homomorphic public key and a homomorphic secret key through a multi-party operation with other data processing devices participating in the multi-party operation in the TEE area—where the piece of the homomorphic secret key is stored in the second area—the processor obtaining a homomorphic ciphertext corresponding to the result of a homomorphic operation of the data requiring the multi-party operation of the plurality of data processing devices encrypted with the homomorphic public key, and the processor decrypting the homomorphic ciphertext through a multi-party operation using the piece of the homomorphic public key in the TEE area to obtain a decryption result.

[0011] Additionally or alternatively, the operation may include the processor comparing the decryption result in the TEE region with the decryption result obtained in the TEE region of each of the other data processing devices, and determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have been maintained in response to all decryption results matching.

[0012] Additionally or alternatively, the operation may include the processor determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have not been maintained in response to at least one of the all decryption results not matching another decryption result.

[0013] Additionally or alternatively, the above operation may include the processor obtaining homomorphically encrypted data by homomorphically encrypting the data requiring multi-party operation stored in the memory using the homomorphic public key obtained in the TEE area.

[0014] Additionally or alternatively, the operation may include the processor receiving homomorphically encrypted data using the homomorphic encryption public key from each of the other data processing devices, and obtaining a homomorphic ciphertext by performing a homomorphic operation on the acquired homomorphically encrypted data and the received homomorphically encrypted data.

[0015] Additionally or alternatively, the operation may include the processor transmitting the acquired homomorphic ciphertext to the TEE area.

[0016] Additionally or alternatively, the above operation may include the processor determining the decryption result as the final result of the homomorphic encryption-based multi-party operation.

[0017] According to another embodiment of the present invention, a device for data processing is proposed, wherein the device comprises: a transceiver configured to provide communication with other data processing devices and utilizing a multi-party operation based on homomorphic encryption; a memory configured to store code for performing operations for data processing using the multi-party operation based on homomorphic encryption; and a processor including a Trusted Execution Environment (TEE) for executing the code, wherein the memory may include a first region configured to store data requiring the multi-party operation and a second region configured to store or install the TEE. The above operation may include the processor obtaining a piece of a homomorphic public key and a homomorphic secret key through a multi-party operation with the TEE of the data processing devices participating in the multi-party operation in the TEE, wherein the piece of the homomorphic secret key is stored in the second area, and the processor obtaining a homomorphic ciphertext corresponding to the result of a homomorphic operation of the data requiring the multi-party operation of the data processing devices participating in the multi-party operation, which is encrypted with the homomorphic public key, and the processor decrypting the homomorphic ciphertext through a multi-party operation using the piece of the homomorphic public key in the TEE to obtain a decryption result.

[0018] The above-mentioned problem-solving methods are merely some of the embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by those skilled in the art based on the detailed description of the present invention to be described below. Effects of the invention

[0019] The present invention has the following effects.

[0020] The present invention can reduce the amount of communication in multi-party operations while maintaining the confidentiality and integrity of data.

[0021] The effects according to the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the following detailed description of the invention. Brief explanation of the drawing

[0022] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present invention, provide embodiments of the present invention and explain the technical concept of the present invention together with the detailed description. Figure 1 is a diagram illustrating the concept of multilateral operation. Figure 2 is a diagram illustrating the concepts of homomorphic encryption and homomorphic operations. FIGS. 3 and FIGS. 4 are drawings illustrating a homomorphic encryption-based multi-party computation system according to the present invention. FIG. 5 is a block diagram of a data processing device according to the present invention. FIG. 6 is a block diagram of a memory of a data processing device according to the present invention. Specific details for implementing the invention

[0023] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols will be assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles. Furthermore, in describing embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification; the technical concept disclosed in this specification is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention.

[0024] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0025] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0026] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0027] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0029] A TEE is a secure computational area that isolates the processor from accessing sensitive data and operations. A TEE can be understood as a logical area within the processor. A TEE is installed or stored in a specific area (e.g., a security area) of a storage medium, such as memory, and may include an OS or applications. Hereinafter, it will be referred to as the “TEE area.”

[0030] By performing security-critical operations within a TEE area isolated from the outside, data integrity and confidentiality can be maintained even if the operating system is overturned.

[0031] Fully homomorphic encryption maintains the confidentiality of the original data by enabling direct computation without decrypting the encrypted data. Therefore, even if a third party or a third-party server processes sensitive data, its contents are not exposed.

[0033] The protocol proposed in this specification consists of a system composed of N data-owning entities and communication between them. Each entity may consist of a data management server and a TEE area. FIG. 3 shows a block diagram of a plurality of data-owning entities according to the present invention. FIG. 3 illustrates the logical or software configuration of each data-owning entity (10-1, 10-2, …, 10-n). Meanwhile, in FIG. 3 and FIG. 4 to be described later, communication between each entity is depicted as one-to-one, but unlike what is depicted, one-to-many (1:N) communication may be established. That is, since multi-party operations are basically used, as shown in FIG. 1, each entity can establish a communication connection with all other entities.

[0034] The TEE area is an environment where a processor executes or performs computations and corresponds to a logical area; however, in the following description, the "TEE module" will be referred to as the entity executing computations or operations within the TEE area. The TEE module is the entity that executes the operations proposed in this invention within the TEE area, and in terms of hardware configuration, it can be understood that the processor executes the corresponding operations within the TEE area.

[0035] Additionally, for the sake of convenience of explanation, it is referred to as a “data management server,” but the data management server may correspond to a processor that executes operations, etc., in an environment other than the TEE area (non-TEE area).

[0036] TEE modules are trusted entities, data management servers are not trusted, and all external entities are not trusted at all. Communication between external entities is divided into general communication between servers (T1) and TEE communication between TEEs (T2), and both types of communication are end-to-end encrypted. General communication prevents data leakage / tampering by all external entities, and TEE communication prevents data leakage / tampering by external entities and data management servers. Additionally, within the data-owning entity, a communication interface (C1) between the TEE module (11) and the data management server (12) can be configured.

[0037] The goal of the proposed protocol is to enable multiple data management servers to combine their data to perform public operations (i.e., MPC operations) (e.g., statistical calculations such as the average of all data or complex calculations such as machine learning training / inference), while preventing each data owner from obtaining information about data owned by external servers that is not their own during this process.

[0038] In particular, the unique value obtained by each data owner is the final result of a public operation. It is assumed that data management servers honestly homomorphically encrypt the data they own without tampering and share it with other servers; however, regarding homomorphically encrypted data received from other data management servers, all types of tampering and confidentiality leakage attacks can be carried out during the process of transmitting it to their TEE modules. Furthermore, each data management server can collude with other data management servers, and if not even a single data management server participates in the collusion, this protocol is safe from data leakage or tampering attacks.

[0040] FIG. 4 is a figure showing a multi-party computation system based on homomorphic encryption according to the present invention.

[0041] FIG. 4 illustrates an example in which the data-owning entities shown in FIG. 3 are represented as a hardware configuration, and three data-owning entities (10-1, 10-2, 10-3) constitute a system according to the present proposal.

[0042] Each data-owning entity includes a processor (101-1, 101-2, 101-3) and may include memory and a transceiver, although not illustrated. Additionally, the data-owning entities will be referred to as “data processing devices” below.

[0043] Additionally, the processor of each data processing device is configured to have an area divided into a TEE area (10) and a non-TEE area (20), and decryption using a homomorphic encryption secret key is configured to be performed in the TEE area (10). A general OS or general app cannot access the TEE area (10) and is configured to run in the non-TEE area (20). Therefore, a general OS or general app cannot use the homomorphic encryption secret key.

[0044] The protocol according to the present proposal consists of a total of 7 steps, and each step will be explained sequentially.

[0045] Additionally, a protocol in one data processing device (10-1) is described, and this is applied or used in the same way in the protocol in the remaining data processing devices.

[0046] S1: Generation of common homomorphic public key and homomorphic private key

[0047] The processor (101) of all data processing devices (10) participating in the protocol may be configured to perform multi-party communication in or through the TEE area and to generate a common homomorphic public key and secret key through consensus.

[0048] This consensus generates homomorphic key pairs (i.e., homomorphic public and private keys) using MPC by treating the sum of random numbers generated in the TEE area of ​​each data processing unit as a seed value. The result of the operation is a homomorphic public key (including the encryption key, bootstrapping key, re-linear key, and Galois key) and shares of the homomorphic private key, and each data processing unit possesses one complete homomorphic public key and one share of the homomorphic private key. At this time, access to the shares of the homomorphic private key is restricted to the TEE area only, and accordingly, only the previously described TEE module can be used.

[0049] S2: Transmit homomorphic public key

[0050] The processor (101-1) of the data processing unit (10-1) can be configured to transfer the acquired homomorphic public key from the TEE area (10-1) to the non-TEE area (20-1). Thus, the processor can use the homomorphic public key in the non-TEE area (20-1). The acquired homomorphic secret key fragment is still restricted to being accessible only in the TEE area (10-1).

[0051] S3: Homomorphic encryption of data (using homomorphic public key)

[0052] The processor (101-1) can be configured to encrypt data requiring multi-party operation of the data processing device (10-1) in the non-TEE area (20-1) using a homomorphic public key.

[0053] S4: Sharing homomorphic encrypted data and homomorphic operations on all homomorphic encrypted data

[0054] The processor (101-1) of the data processing unit (10-1) can be configured to share homomorphically encrypted data in the non-TEE area (20-1) with all data processing units (10-2, 10-3) participating in multi-party operations. Accordingly, each data processing unit can obtain the homomorphically encrypted data of all data processing units, and among these, it cannot know what value other data is other than the data it encrypted. This is because the homomorphic encryption secret key cannot be accessed in the processor's non-TEE area (20).

[0055] Meanwhile, when data processing devices transmit homomorphically encrypted data to each other, they encrypt the corresponding homomorphic ciphertext using an end-to-end encryption protocol (e.g., TLS (Transport Layer Security)). This is because homomorphic ciphertext only protects data confidentiality and offers no method to verify tampering. To address this issue, transmitting homomorphic ciphertext via TLS allows for the detection of data tampering during transit at the TLS communication stage, thereby preventing the embarrassing homomorphic processing of the tampered data.

[0056] Additionally, the processor (101-1) of the data processing unit (10-1) may be configured to perform homomorphic operations on the homomorphic encrypted data it has encrypted and the homomorphic encrypted data shared from other data processing units, that is, the homomorphic encrypted data of all data processing units. The homomorphic operation consists of operations such as addition, multiplication, slot rotation, and bootstrapping, and no intermediate communication with other data processing units is required until the entire homomorphic operation is completed. Meanwhile, the homomorphic operation is a common operation formula that all data processing units perform identically.

[0057] S5: Pass the homomorphic ciphertext to the TEE area

[0058] The processor (101-1) of the data processing device (10-1) is configured to transmit the homomorphic ciphertext corresponding to the result value derived to the TEE area (10-1) after completing all homomorphic operations.

[0059] S6: Homomorphic ciphertext decryption in the TEE area via MPC and comparison of decryption results obtained in each TEE area

[0060] The processor (101-1) of the data processing device (10-1) can be configured to obtain a decryption result by decrypting the homomorphic ciphertext it has obtained through multi-party operations with other data processing devices using the homomorphic cipher secret key fragment described above in the TEE area (10-1). Additionally, the processor (101-1) of the data processing device (10-1) can be configured to receive the result of decrypting the homomorphic ciphertext obtained from other data processing devices (10-2, 10-3) in the TEE area (10-1), i.e., the decryption result, and to compare this with the decryption result it has obtained.

[0061] S7: Transmit decoding result

[0062] The processor (101-1) of the data processing unit (10-1) may treat the decoding result as data with maintained confidentiality and / or integrity if its decoding result matches the decoding results of other data processing units. In this case, the processor (101-1) of the data processing unit (10-1) may be configured to transmit the decoding result back to the non-TEE area (20-1). This allows the result of the multi-party operation to be accessed from a general app or OS of the processor (101-1).

[0063] Meanwhile, FIG. 4 describes a TEE area and a non-TEE area being set in a single processor (101-1) of a single device (10-1), and a procedure (S1 to S7) according to the proposed technology being executed by the single processor (101-1). However, in the present invention, a single device (10-1) may include one or more processors, and if multiple processors are included, it may include a processor for the TEE area and a processor for the non-TEE area. In such a case, the previously described S1, S2, S6, S7, etc., may be performed by the processor for the TEE area. That is, the previously described TEE module may include a processor, and this processor may be configured to perform S1, S2, S6, S7, etc. of FIG. 4.

[0065] All data tampering by external entities, excluding entities participating in the multi-party operation, as proposed in this specification, can be blocked by end-to-end encryption in general communication (T1) or TEE communication (T2). Furthermore, if a specific data processing device tampers with a homomorphic ciphertext that has encrypted data from another data processing device received with malicious intent, the homomorphic operation result value based on the tampered data can be identified as being different from the decryption result obtained in the TEE area of ​​the other data processing device during the procedure of decrypting and verifying through multi-party operation in the TEE area at S6 of FIG. 4, thereby detecting the data tampering with the homomorphic ciphertext.

[0066] Even if multiple data processing devices conspire to tamper with homomorphic ciphertexts in the same manner, if even a single data processing device among all data processing devices participating in this protocol does not participate in the conspiracy to tamper with data, the fact of data tampering in all other TEE areas can be detected through the decoding process in the TEE area of ​​the data processing device that did not participate in the conspiracy.

[0067] Furthermore, each data processing unit can only know the final result of an operation in the non-TEE area and cannot access intermediate values, because only the final result is decrypted in the TEE area and transmitted to the non-TEE area. Intermediate values ​​or fragments of the homomorphic secret key are stored or used only in the TEE area, and are inaccessible in areas outside the TEE.

[0068] Furthermore, even if one TEE area of ​​all data processing units is exposed to a side-channel attack, each TEE area possesses or stores fragmented homomorphic secret keys, so the intact homomorphic secret key is not exposed.

[0069] Meanwhile, data processing devices may attempt back-inference attacks on input data based on the final operation result; the success of such back-inference is determined by the number of data used in the intermediate homomorphic encryption operation (corresponding to the number of variables in the operation) and the complexity of the operation. Such back-inference attacks on input data are considered to be outside the scope of security guarantees of this protocol.

[0070] If only MPC and FHE (Fully Homomorphic Encryption) are used without utilizing the TEE area, fragments of the homomorphic secret key are held or stored in the non-TEE area. In this case, if n' data processing units out of a total of n data processing units conspire to tamper with data while n - n' units do not participate in the conspiracy, data confidentiality is compromised if the n - n' units are exposed to an attack and the homomorphic secret key fragments are leaked to the units participating in the conspiracy. However, according to the technology proposed in this invention, since the TEE area is utilized, homomorphic secret key fragments are inaccessible in the non-TEE area, making it very difficult for them to be leaked to other data processing units.

[0071] If only one data processing unit uses the TEE area and the remaining data processing units do not use the TEE area, the TEE area of ​​that single data processing unit becomes a single point of failure, which poses a security burden. However, if all data processing units use the TEE area and use or store fragments of the homomorphic encryption secret key in the TEE area, security can be guaranteed because the homomorphic encryption secret key can only be recovered by overturning the TEE area of ​​all data processing units.

[0073] In addition, the proposed technology is particularly effective in cases where communication volume is significantly high when using only MPC. Specifically, the MPC communication volume increases as the number of data processing devices (data owners) increases. Meanwhile, since FHE operations are independent of the number of data owners, the efficiency of FHE operations increases as the number of data owners increases. Therefore, the efficiency of this technology increases as the number of data owners increases.

[0074] In other words, using this technology, MPC operations are performed only at the beginning and end of the procedure between the TEE regions of the data processing devices, and intermediate data processing operations are performed locally on each data processing device using homomorphic encryption. Therefore, even if the number of data processing devices increases, the rate of increase in communication volume is significantly small, making communication efficient. This aspect of communication efficiency has the advantage of much higher usability in actual services, as not all devices need to synchronize to process operations.

[0075] Furthermore, in the case of techniques using only FHE without MPC or TEE areas, data processing operations become impossible because it is technically difficult to unify homomorphic keys of different ciphertexts; whereas, using the proposed technique enables data processing operations by deriving a common homomorphic key based on MPC communication between the TEE areas of different data processing devices.

[0077] FIG. 5 illustrates a block diagram of a data processing device (10) according to the present invention.

[0078] The data processing device (10) is configured to perform multi-party operations based on homomorphic encryption with other data processing devices.

[0079] The data processing device (10) may be configured to include a memory (100), a processor (101), and a transceiver (102).

[0080] The memory (100) may be configured to store code for performing operations for data processing using homomorphic encryption-based multi-party operations. Additionally, the memory (100) may include at least two regions (1001, 1002) as illustrated in FIG. 6. Data requiring multi-party operations may be stored in the first region, and the second region may be configured to store or install a TEE. The second region is an area accessible from the TEE region, and access is restricted in the non-TEE region (i.e., non-TEE region).

[0081] The transceiver (102) is configured to provide communication with other data processing devices. More specifically, the transceiver (102) may be configured to provide a communication interface for general communication (T1) and TEE communication (T2) as described above with reference to FIG. 3.

[0082] The processor (101) may be configured to execute code stored in memory (100) or to support execution in the TEE area.

[0083] The processor (101) may be configured to obtain a piece of a homomorphic public key and a homomorphic secret key through multi-party operations with the remaining data processing devices participating in multi-party operations in the TEE area. The obtained piece of the homomorphic secret key may be stored in a second area of ​​memory (100).

[0084] The processor (101) may be configured to obtain a homomorphic ciphertext corresponding to the result of a homomorphic operation of data requiring multi-party operation of multiple data processing devices encrypted with a homomorphic public key. This may be done in an area other than the TEE (non-TEE area) of the processor (101).

[0085] The processor (101) may be configured to obtain a decryption result by decrypting the homomorphic ciphertext through the multi-party operation using a piece of the homomorphic public key in the TEE area.

[0086] Additionally, the processor (101) may be configured to compare the decryption result in the TEE area with the decryption result obtained in the TEE area of ​​each of the other data processing devices, and to determine that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have been maintained in response to all decryption results matching. The processor (101) may be configured to determine the decryption result as the final result of the homomorphic encryption-based multi-party operation. Accordingly, the processor (101) may be configured to transmit the decryption result to a non-TEE area.

[0087] Additionally, the processor (101) may be configured to determine that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have not been maintained in response to at least one of all decryption results not matching another decryption result. In this case, the processor may be configured to ignore or delete the decryption result.

[0088] The processor (101) can be configured to obtain homomorphically encrypted data by homomorphically encrypting data requiring multi-party operations stored in memory (100) using a homomorphic public key obtained in the TEE area.

[0089] Additionally, the processor (101) may be configured to receive homomorphically encrypted data from each of the other data processing devices in the non-TEE area using the homomorphic encryption public key, and to obtain a homomorphic ciphertext by performing a homomorphic operation on the acquired homomorphically encrypted data and the received homomorphically encrypted data.

[0090] The processor (101) can be configured to transmit the acquired homomorphic ciphertext to the TEE area.

[0092] Meanwhile, operations, processes, etc. described with reference to FIG. 3 and FIG. 4, which are not described with reference to FIG. 5, may be performed by the device (10) or processor (101).

[0094] In addition, as another aspect of the present invention, the operation of the above-described proposal or invention may be provided as code that can be implemented, practiced, or executed by a "computer" (a comprehensive concept including a system on chip (SoC) or (micro)processor, etc.), or as a computer-readable storage medium or computer program product that stores or contains said code, and the scope of the present invention may be extended to said code or as a computer-readable storage medium or computer program product that stores or contains said code.

[0096] The detailed description of the preferred embodiments of the present invention disclosed above is provided to enable those skilled in the art to implement and practice the present invention. Although the present invention has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention as described in the following claims. Accordingly, the present invention is not intended to be limited to the embodiments shown herein, but to be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

Claim 1 As a system for data processing, the system comprises a plurality of data processing devices configured to perform data processing using homomorphic encryption-based multi-party operations, and each of the plurality of data processing devices comprises: a transceiver configured to provide communication with other data processing devices; and a memory configured to store code for performing operations for data processing using homomorphic encryption-based multi-party operations. A system comprising a processor that supports execution in a Trusted Execution Environment (TEE) area for executing the code above, wherein the memory includes a first area configured to store data requiring the multi-party operation and a second area configured to store or install the TEE, and the operation comprises: the processor obtaining a piece of a homomorphic public key and a homomorphic private key through a multi-party operation with other data processing devices participating in the multi-party operation in the TEE area - wherein the piece of the homomorphic private key is stored in the second area -, wherein the processor obtains a homomorphic ciphertext corresponding to the result of the homomorphic operation of the data requiring the multi-party operation of the plurality of data processing devices encrypted with the homomorphic public key, and wherein the processor decrypts the homomorphic ciphertext through a multi-party operation using the piece of the homomorphic public key in the TEE area to obtain a decryption result. Claim 2 A system according to claim 1, wherein the operation comprises: the processor comparing the decryption result obtained in the TEE region with the decryption result obtained in the TEE region of each of the other data processing devices, and determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have been maintained in response to all decryption results matching. Claim 3 A system according to paragraph 2, wherein the operation comprises the processor determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have not been maintained in response to at least one of all decoding results not matching another decoding result. Claim 4 A system according to claim 1, wherein the operation comprises: the processor homomorphically encrypting the data requiring multi-party operation stored in the memory using the homomorphic public key obtained in the TEE area to obtain homomorphically encrypted data. Claim 5 A system according to claim 4, wherein the operation comprises: the processor receiving homomorphically encrypted data using the homomorphic encryption public key from each of the other data processing devices, and performing a homomorphic operation on the acquired homomorphically encrypted data and the received homomorphically encrypted data to obtain a homomorphic ciphertext. Claim 6 In paragraph 5, the above operation comprises: the processor transmitting the acquired homomorphic ciphertext to the TEE area, a system. Claim 7 In paragraph 2, the operation comprises: the processor determining the decryption result as the final result of the homomorphic encryption-based multi-party operation, a system. Claim 8 A device for data processing, wherein the device utilizes homomorphic encryption-based multi-party operations and comprises a transceiver configured to provide communication with other data processing devices; and a memory configured to store code for performing operations for data processing using the homomorphic encryption-based multi-party operations. A device comprising: a processor including a Trusted Execution Environment (TEE) that executes the code above; wherein the memory includes a first region configured to store data requiring the multi-party operation and a second region configured to store or install the TEE, and the operation comprises: the processor obtaining a piece of a homomorphic public key and a piece of a homomorphic private key through a multi-party operation with the TEE of data processing devices participating in the multi-party operation in the TEE, wherein the piece of the homomorphic private key is stored in the second region; wherein the processor obtains a homomorphic ciphertext corresponding to the result of the homomorphic operation of the data requiring the multi-party operation of the data processing devices participating in the multi-party operation, which is encrypted with the homomorphic public key; and wherein the processor decrypts the homomorphic ciphertext through a multi-party operation using the piece of the homomorphic public key in the TEE to obtain a decryption result. Claim 9 A device according to claim 8, wherein the operation comprises: the processor comparing the decryption result obtained in the TEE with the decryption result obtained in the TEE of each of the other data processing devices participating in the multi-party operation, and determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have been maintained in response to all decryption results matching. Claim 10 A device according to claim 9, wherein the operation comprises determining that the integrity and confidentiality of the homomorphic encryption-based multi-party operation have not been maintained in response to at least one of all decryption results not matching another result.

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