Privacy-preserving data sharing method for medical Internet of Things based on oblivious transfer

Abstract

The present invention discloses a privacy-protected data sharing method for the medical Internet of Things based on oblivious transmission. A trusted institution selects an elliptic curve and specifies corresponding parameters and makes them public, and all participants generate public-private key pairs and register with the trusted institution. The data owner obtains an encryption key through XOR and elliptic curve midpoint multiplication, and uses the encryption key to encrypt all data, sends the encrypted data to a cloud server, and then divides the encryption key into m shares through Shamir threshold secret sharing, and distributes these m shares to each edge server. The data user initiates oblivious transmission, thereby obtaining k shares, and recovering the encrypted data through Lagrange interpolation. The elliptic curve encryption scheme, hash and XOR operations used in the present invention greatly improve the efficiency in the sharing process. In addition, the oblivious transmission protocol realizes two-way privacy protection and provides higher security.

Description

Technical Field

[0001] The present invention relates to the technical field of medical Internet of Things, and in particular to a privacy-preserving data sharing method for medical Internet of Things based on inadvertent transmission. Background Art

[0002] With the development of the healthcare industry, healthcare uses cloud computing, the Internet of Things, and remote healthcare technologies to share data among various stakeholders. IoT devices in the healthcare field, including smart edge devices such as wearable sensors, are continuously increasing medical data. If data is monitored or stolen by malicious users during the sharing process, it will endanger the patient's disease, behavior, and habits, and infringe on user privacy. Therefore, the privacy and security of health data are becoming important issues. Many existing solutions use pairing and bilinear mapping. The bilinear pairing operation has a very high computational cost and is not suitable for deployment in a medical IoT environment using wearable sensors, a resource-constrained device. In addition, in real life, cloud servers are often untrustworthy, and the assumption of full trust in cloud servers exposes data to serious security and privacy threats.

[0003] Elliptic curve cryptography is a public key encryption technology, referred to as ECC, which is an asymmetric encryption algorithm based on the mathematical theory of elliptic curves. RSA encryption is an asymmetric encryption algorithm. Compared with RSA, ECC has the advantage of using shorter keys to achieve security comparable to or higher than RSA. A 160-bit ECC key has the same security as a 1024-bit RSA key.

[0004] Edge servers are used to solve the trust issue of cloud servers because they can assist in processing and storing personal information, which can reduce the burden on cloud servers. It is also beneficial to transfer some functions from cloud servers to edge servers. With the help of edge servers, patients can upload data securely. Summary of the invention

[0005] In order to make up for the deficiencies in security and efficiency of the existing technology, the present invention provides a privacy-preserving data sharing method for medical Internet of Things based on oblivious transmission.

[0006] The method of the present invention comprises the following steps:

[0007] 1) System parameter initialization:

[0008] The trusted institution generates the curve E and base point G of the elliptic curve cryptography system, generates a hash function and a system public and private key pair, and publishes the public key;

[0009] 2) The data owner generates a set S of data users that are allowed to access the data;

[0010] 3) Data users request a license from a trusted institution;

[0011] 4) The data owner encrypts the medical information and then sends the encrypted data to the cloud server;

[0012] 5) For each encrypted data, the data owner generates a k-1 order polynomial, divides the encryption key into m shares through this polynomial, and distributes these m shares to a group of edge servers. Each edge server verifies the correctness of the share through a hash function;

[0013] 6) For the data that the data user wants to obtain, the data user inadvertently transmits it to the edge server that has the key sharing, recovers the encryption key and verifies the correctness of the key;

[0014] 7) The data user initiates verification to the cloud server, and the cloud server performs verification. If the verification is successful, the cloud server sends the encrypted data of the data owner to the data user;

[0015] 8) The data user decrypts the encrypted data sent by the cloud server.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the elliptic curve encryption scheme, hash and XOR operation used in the present invention greatly improves the efficiency in the sharing process compared with encryption operations such as RSA and pairing. In addition, the oblivious transfer protocol realizes two-way privacy protection, provides higher security, and verifies secret sharing through the one-way accumulator of Nyberg's one-way hash function. Through these technical means, the present invention can greatly improve the security and confidentiality of the data sharing process while ensuring efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of information interaction between the parties involved in the present invention. DETAILED DESCRIPTION

[0018] In the present invention, the trusted institution selects the elliptic curve and specifies the corresponding parameters and makes them public. All participants generate public-private key pairs and register with the trusted institution. The data owner obtains the encryption key through XOR and elliptic curve midpoint multiplication, and uses the encryption key to encrypt all data, sends the encrypted data to the cloud server, and then divides the encryption key into m shares through shamir (k, m) threshold secret sharing, calculates the verification data through Nyberg's one-way hash function, and shares these m shares to each edge server. When the edge server receives the share, it can quickly verify the share through Nyberg's one-way hash function, thereby judging whether the share it obtains is correct.

[0019] The data user selects k servers from the m edge servers and initiates an oblivious transfer to them, thereby obtaining k shares, recovering the encrypted data through the Lagrange interpolation method, and then verifying the recovered data through Nyberg's one-way hash function. The data user initiates verification to the cloud server, which verifies whether the license is available and whether the data user's identity identifier ID is in the set S submitted by the data user. If the verification is successful, the encrypted data of the data owner is sent to the data user. The data user decrypts the encrypted data sent by the cloud server to obtain the data.

[0020] like Figure 1 As shown, this embodiment includes the following steps:

[0021] 1) System parameter initialization.

[0022] The trusted institution generates the curve E and base point G of the elliptic curve cryptography system, generates a hash function and a system public and private key pair, and publishes the public key;

[0023] 2) The data owner generates a set S of data users that are allowed to access the data;

[0024] 3) Data users request a license from a trusted institution;

[0025] 4) The data owner encrypts the medical information and then sends the encrypted data to the cloud server;

[0026] 5) For each encrypted data, the data owner generates a k-1 order polynomial, divides the encryption key into m shares through this polynomial, and distributes these m shares to a group of edge servers. Each edge server verifies the correctness of the share through a hash function;

[0027] 6) For the data that the data user wants to obtain, the data user inadvertently transmits it to the edge server that has the key sharing, recovers the encryption key and verifies the correctness of the key through the hash function;

[0028] 7) The data user initiates verification to the cloud server, which performs verification and sends the encrypted data of the data owner to the data user if the verification is successful;

[0029] 8) The data user decrypts the encrypted data sent by the cloud server.

[0030] Preferably, in step 1), the curve E selected by the trusted institution is the Secp256r1 curve, which is in the form of y2=x 3+ax+b,a=FFFFFFFF 00000001 00000000 00000000 00000000FFFFFFFF FFFFFFFF FFFFFFFC,b=5AC635D8 AA3A93E7 B3EBBD55 769886BC 651D06B0 CC53B0F6 3BCE3C3E 27D2604B.

[0031] Preferably, in step 2), the set S generated by the data owner contains the unique identifiers ID of all data users, and the data owner sends the set S to the cloud server, and the set S helps the cloud server determine the eligibility of the data user to access the data owner's data.

[0032] Preferably, in step 4): an encryption key needs to be obtained before the encryption process. To obtain the encryption key, the random number in the finite field of the elliptic curve must be XORed first, and then the random number after the XOR operation is multiplied by the base point G. Compared with pairing and other asymmetric encryption operations, XOR and point multiplication operations greatly improve encryption efficiency.

[0033] Preferably, in step 5), secret sharing is implemented by the Shamir (k, m) threshold secret sharing scheme. For each encryption key, the data owner generates a k-1 order polynomial Among them, a 0 is the encryption key, X i is the horizontal coordinate of the edge server public key on the elliptic curve, and m shares are obtained. The data owner distributes these m shares to m edge servers and calculates the verification data through Nyberg's one-way hash function. Each edge server can quickly verify the shares.

[0034] Preferably, in step 6), k shares are obtained through the 1-out-of-n oblivious transfer protocol. In this process, the edge server does not know which share the data user has obtained. The data user can only obtain the share he wants and does not know other shares of the edge server. The encrypted data is restored through the Lagrange interpolation method, and the restored data is verified through the Nyberg one-way hash function.

[0035] Preferably, the cloud server performs verification in step 7) by specifically checking whether the license is available and whether the data user identity identifier ID is in the set S submitted by the data user.

[0036] In summary, the present invention improves the data sharing process in terms of security and efficiency, realizes lightweight computing, further improves the efficiency of transmission between data users and data owners, and reduces communication overhead and computing overhead. The present invention uses oblivious transmission to ensure two-way security between data users and edge servers, introduces Shamir threshold secret sharing and edge servers to reduce the burden on cloud servers, and provides verifiable functions through Nyberg's one-way hash function. Through the above technical means, the present invention can greatly improve the security and confidentiality of the sharing process while ensuring efficiency.

Claims

1. A privacy-preserving data sharing method for medical Internet of Things based on oblivious transmission, characterized in that The method comprises the following steps: Step 1) System parameter initialization: The trusted institution generates the curve E and base point G of the elliptic curve cryptography system, generates a hash function and a system public and private key pair, and publishes the public key; Step 2) The data owner generates a set S of data users that are allowed to access the data; Step 3) The data user requests a license from a trusted institution; Step 4) The data owner encrypts the medical information and then sends the encrypted data to the cloud server; Step 5) For each encrypted data, the data owner generates a k-1 order polynomial, divides the encryption key into m shares through this polynomial, and distributes these m shares to a group of edge servers. Each edge server verifies the correctness of the share through a hash function; Step 6) For the desired data, the data user inadvertently transmits it to the edge server that has the key sharing, recovers the encryption key and verifies the key correctness; Step 7) The data user initiates verification to the cloud server, which performs verification. If the verification is successful, the cloud server sends the encrypted data of the data owner to the data user; Step 8) The data user decrypts the encrypted data sent by the cloud server; In step 2), the data user set S contains the unique identifiers ID of all data users; In step 4), the encryption key needs to be obtained before the encryption process. To obtain the encryption key, the random number in the finite field of the elliptic curve is first XORed, and then the random number after the XOR operation is multiplied with the base point G; The cloud server verification process in step 7) includes: checking whether the license is available, and checking whether the data user identity identifier ID is in the data user set S.

2. The privacy-preserving data sharing method for the medical Internet of Things based on oblivious transmission according to claim 1 is characterized in that: In step 1), the curve E selected by the trusted institution is the Secp256r1 curve.

3. The privacy-preserving data sharing method for medical Internet of Things based on oblivious transmission according to claim 1 is characterized in that: In step 5), secret sharing is implemented by Shamir’s secret sharing scheme, and edge server verification sharing is implemented by a one-way accumulator of Nyberg’s one-way hash function.

4. The privacy-preserving data sharing method for the medical Internet of Things based on oblivious transmission according to claim 1 is characterized in that: In step 6), the oblivious transfer adopts the 1-out-of-n oblivious transfer protocol, and the recovery of encrypted data is achieved through the Lagrange interpolation method.

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