CN107580003A - Secure certificate-less searchable public-key encryption scheme for industrial internet of things - Google Patents

Abstract

Public key cryptography scheme is can search for without certificate the invention discloses a kind of provable security under industrial environment of internet of things, it comprises the following steps：A, registration phase：Data consumer generates respective public key and private key with Cloud Server under the assistance of key generation centre；B, data encryption stage:Ciphertext is simultaneously uploaded to Cloud Server by data owner's encryption keyword.C, retrieval phase：Data consumer generates the trapdoor for retrieval and is sent to Cloud Server, and Cloud Server is received after the trapdoor of user, it will ciphertext is retrieved, and the result of retrieval is returned into user.The present invention is directed to the keyword guessing attack that malicious server and external attacker be present in industrial Internet of Things cloud storage and proposes new solution, and the provable offline keyword guessing attack that can keep out external attacker and malicious server, there is higher safe class in similar security protocol.

Description

Secure certificate-less searchable public-key encryption scheme for industrial internet of things

technical field

The present invention proposes a certificate-free searchable public key encryption scheme that can be proven safe in the industrial Internet of Things environment.

Background technique

With the rapid development of the Industrial Internet of Things (IIoT), cloud storage technology of the Industrial Internet of Things (IIoT) is favored by more and more enterprises and individual users. A typical Industrial Internet of Things (IIoT) cloud storage network environment is shown in Figure 1: In this environment, enterprises collect data in industrial production and operation, while sensors collect external information, and these data will be uploaded to cloud servers through the network, and Interact with computing servers and storage servers. However, cloud data is not under the supervision of enterprises and individual users, so in order to prevent the leakage of private information, the data needs to be encrypted before uploading to the cloud. This creates a new problem: because the cloud server does not have the key to decrypt the data, the cloud server cannot respond when the data user wants to retrieve the cloud data.

Aiming at this problem, many scholars have proposed a large number of solutions. However, in many current researches, many schemes have been proved to have security problems, and many without security problems use traditional public key encryption schemes, which will bring about certificate management problems and secret key exchange problems. Less applicable in Industrial Internet of Things (IIoT) environments. The recently proposed multi-keyword searchable encryption without secure channel (SCF-MCLPEKS) scheme uses a certificateless public key encryption system to solve the problems of certificate management and key escrow, but it cannot resist offline keyword guessing attacks. Therefore, when a malicious server or an external attacker monitors the public channel, the private information in the query request of the data user will be leaked, and the encrypted data stored in the cloud will also be leaked.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defect that existing schemes cannot withstand offline keyword attacks by external attackers or malicious servers, and provide a certificate-free searchable public key encryption scheme that ensures trapdoor security in the industrial Internet of Things environment .

In order to solve the above-mentioned technical problems, the present invention conducts extended research based on the architecture of Figure 2: first, the data owner uses the public key of the server and the public key of the data user to encrypt the keyword and upload it to the cloud. Then, the data user uses the server's public key to perform calculations on keywords, generates a trapdoor for retrieval and sends it to the cloud server through an open channel. After receiving the trapdoor, the cloud server retrieves the ciphertext and returns the result to the user. In the present invention, since the public key of the server is used when the data user generates the trapdoor for retrieval in the retrieval phase, the attacker cannot obtain the private key of the specified server, and thus cannot implement an offline keyword guessing attack , thereby ensuring the privacy of user data.

According to above principle, the present invention provides following technical scheme:

The present invention provides a provably safe searchable public key encryption scheme without a certificate under the environment of the Industrial Internet of Things, comprising the following steps:

A. Registration phase: data users The server (Cloud server) generates its own public key and private key with the assistance of the Key Generation Center (KGC);

A1: System Settings: This function is executed by the Key Generation Center (KGC) to generate some system parameters.

1) Input: a security parameter k , choose a bilinear map e : G ₁ ×G ₁ →G ₂ .

2) Randomly select s ∈ Z _q ^* and P ∈ G ₁ , and calculate P _pub = sP .

3) Set the master key msk = s , and output the public parameter param :

param ={ k , G ₁ , G ₂ , e , q , P , P _pub , H ₁ , H ₂ }, where H ₁ , H ₂ are 2 different hash functions. H ₁ : {0,1} ^* →G ₁ , H ₂ : {0,1} ^* →G ₁ .

A2: Generate a partial private key: This function is executed by the Key Generation Center (KGC) to generate a partial private key of the server or user.

1) Calculation: Q _S = H ₁ ( ID _S ), Q _R = H ₁ ( ID _R ).

2) Calculate D _S = s∙Q _S , D _R = s∙Q _R .

₃ ) Send _DS and DR to the server and user respectively .

A3: Generate secret value: This function is executed by the server or user to generate another part of the private key of the server or user.

1) The server randomly selects a number x _S .

2) The user randomly selects a number x _R .

A4: Set private key: This function is executed by the server or user to generate the private key of the server or user.

1) The server sets its own private key as: SK _S ={ SK _{S ,1} , SK _{S ,2} }={ x _S , D _S }.

2) The user sets his own private key as: SK _R ={ SK _{R, 1} , SK _{R ,2} }={ x _R , D _R }.

A5: Set public key: This function is executed by the server or user to generate the public key of the server or user.

1) The server sets its own public key as: PK _S = x _S ∙ P

2) The user sets his own public key as: PK _R = x _R ∙ P .

B. Data encryption stage:

Encrypted Keyword (SCF-MCLPEKS ⁺ ): This function is executed by the data owner to encrypt the key word. If the data owner wants to send his data to the data user, he can encrypt the keyword set W in the following way:

1) For each keyword w _i ∈ W , choose a random number r _i ,

2) Calculate Q _R = H ₁ ( ID _R ).

3) Calculate U _i , V _i , K _i as follows:

U _i = e ( r _i H ₂ ( w _i ), PK _R )∙ e ( r _i Q _R , P _pub ),

V _i = r _i PK _S ,

K _i = r _i P .

4) Set the ciphertext as: C ={ C _i }, where C _i ={ U _i , V _i , K _i }.

C. Retrieval stage:

C1: Generate trapdoor: This function is executed by the data user to generate a trapdoor for retrieval. If the user of the data wants to retrieve a certain ciphertext with the keyword w , he can generate a trapdoor for retrieval according to the following method:

1) Calculate and choose a random number r .

2) Set trapdoor T _w as: T _w ={ T ₁ , T ₂ }, where T ₁ , T ₂ are as follows:

T ₁ = D _R + x _R ∙ H ₂ ( w ) + rP ,

T ₂ = rPK _S .

(8) Test: This function is executed by the server to test whether the ciphertext C and the trapdoor T _w match.

1) For each ciphertext C _i ∈ C , calculate U = ( U _i ) ^xS .

2) Verification: e ( T ₁ , V _i ) = U ∙ e ( K _i , T ₂ ). If true, return 1, otherwise, return 0.

If w = w _i , then we can get:

e ( T ₁ , V _i )

= e ( D _R + x _R ∙ H ₂ ( w ) + rP , r _i PK _S )

= e ( x _R ∙ H ₂ ( w ), r _i PK _S )∙ e ( D _R , r _i PK _S )∙ e ( rP , r _i PK _S )

= e ( r _i ∙ H ₂ ( w ), x _R PK _S )∙ e ( sQ _R , r _i PK _S )∙ e ( r _i P , rPK _S ).

= [ e ( r _i ∙ H ₂ ( w ), x _R P )∙ e ( r _i Q _R , sP )] ^xS ∙ e ( K _i , T ₂ )

= ( U _i ) x S ^∙ e ( K _i , T ₂ ).

The beneficial effects achieved by the present invention are:

Aiming at the protection of encrypted data private information in the cloud storage environment of Industrial Internet of Things (IIoT), a provably secure searchable public key encryption scheme without certificates is proposed. It can be proved that this scheme can resist offline keyword guessing attacks, can protect encrypted data very well, and has a higher security level in similar certificateless public key searchable encryption schemes. Moreover, this solution is also relatively high in efficiency and has strong practicability, so it can be applied to the cloud storage environment of the Industrial Internet of Things (IIoT).

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Figure 1 shows a typical Industrial Internet of Things (IIoT) cloud storage network environment.

Figure 2 shows the basic process used by the present invention.

detailed description

The preferred embodiments of the present invention will be described below with reference to the accompanying drawing 2. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

A provably secure searchable public key encryption scheme without a certificate under the industrial Internet of Things environment, which includes the following steps:

A. Registration phase: data users The server (Cloud server) generates its own public key and private key with the assistance of KGC;

A1: System Settings: This function is executed by the Key Generation Center (KGC) to generate some system parameters.

1) Input: a security parameter k , choose a bilinear map e : G ₁ ×G ₁ →G ₂ .

2) Randomly select s ∈ Z _q ^* and P ∈ G ₁ , and calculate P _pub = sP .

3) Set the master key msk = s , and output the public parameter param :

param ={ k , G ₁ , G ₂ , e , q , P , P _pub , H ₁ , H ₂ }, where H ₁ , H ₂ are 2 different hash functions. H ₁ : {0,1} ^* →G ₁ , H ₂ : {0,1} ^* →G ₁ .

A2: Generate a partial private key: This function is executed by the Key Generation Center (KGC) to generate a partial private key of the server or user.

1) Calculation: Q _S = H ₁ ( ID _S ), Q _R = H ₁ ( ID _R ).

2) Calculate D _S = s∙Q _S , D _R = s∙Q _R .

₃ ) Send _DS and DR to the server and user respectively .

A3: Generate secret value: This function is executed by the server or user to generate another part of the private key of the server or user.

1) The server randomly selects a number x _S .

2) The user randomly selects a number x _R .

A4: Set private key: This function is executed by the server or user to generate the private key of the server or user.

1) The server sets its own private key as: SK _S ={ SK _{S ,1} , SK _{S ,2} }={ x _S , D _S }.

2) The user sets his own private key as: SK _R ={ SK _{R, 1} , SK _{R ,2} }={ x _R , D _R }.

A5: Set public key: This function is executed by the server or user to generate the public key of the server or user.

1) The server sets its own public key as: PK _S = x _S ∙ P

2) The user sets his own public key as: PK _R = x _R ∙ P .

B. Data encryption stage:

Encrypted Keyword (SCF-MCLPEKS ⁺ ): This function is executed by the data owner to encrypt the key word. If the data owner wants to send his data to the data user, he can encrypt the keyword set W in the following way:

1) For each keyword w _i ∈ W , choose a random number r _i ,

2) Calculate Q _R = H ₁ ( ID _R ).

3) Calculate U _i , V _i , K _i as follows:

U _i = e ( r _i H ₂ ( w _i ), PK _R )∙ e ( r _i Q _R , P _pub ),

V _i = r _i PK _S ,

K _i = r _i P .

4) Set the ciphertext as: C ={ C _i }, where C _i ={ U _i , V _i , K _i }.

C. Retrieval stage:

C1: Generate trapdoor: This function is executed by the data user to generate a trapdoor for retrieval. If the user of the data wants to retrieve a certain ciphertext with the keyword w , he can generate a trapdoor for retrieval according to the following method:

1) Calculate and choose a random number r .

2) Set trapdoor T _w as: T _w ={ T ₁ , T ₂ }, where T ₁ , T ₂ are as follows:

T ₁ = D _R + x _R ∙ H ₂ ( w ) + rP ,

T ₂ = rPK _S .

(8) Test: This function is executed by the server to test whether the ciphertext C and the trapdoor T _w match.

1) For each ciphertext C _i ∈ C , calculate U = ( U _i ) ^xS .

2) Verification: e ( T ₁ , V _i ) = U ∙ e ( K _i , T ₂ ). If true, return 1, otherwise, return 0.

If w = w _i , then we can get:

e ( T ₁ , V _i )

= e ( D _R + x _R ∙ H ₂ ( w ) + rP , r _i PK _S )

= e ( x _R ∙ H ₂ ( w ), r _i PK _S )∙ e ( D _R , r _i PK _S )∙ e ( rP , r _i PK _S )

= e ( r _i ∙ H ₂ ( w ), x _R PK _S )∙ e ( sQ _R , r _i PK _S )∙ e ( r _i P , rPK _S ).

= [ e ( r _i ∙ H ₂ ( w ), x _R P )∙ e ( r _i Q _R , sP )] ^xS ∙ e ( K _i , T ₂ )

= ( U _i ) x S ^∙ e ( K _i , T ₂ ).

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still The technical solutions recorded in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (2)

1. A safe searchable public key encryption scheme without a certificate under the Industrial Internet of Things environment, characterized in that, comprising the following steps: First, the data owner uses the public key of the server and the public key of the data user to encrypt the keyword and upload it to the cloud; Then, the data user uses the server's public key to perform calculations on keywords, generates a trapdoor for retrieval and sends it to the cloud server through an open channel. After receiving the trapdoor, the cloud server retrieves the ciphertext and returns the result to the user. 2. A security-free certificate-free searchable public key encryption scheme under the Industrial Internet of Things environment according to claim 1, characterized in that the scheme specifically comprises the following steps: A. Registration stage: the data user and the cloud server generate their respective public and private keys with the assistance of the key generation center; A1: Setting: This function is executed by the key generation center to generate some system parameters; 1) Input: a security parameter k , select a bilinear map e : G ₁ ×G ₁ →G ₂ ; 2) Randomly select s ∈ Z _q ^* and P ∈ G ₁ , and calculate P _pub = sP ; 3) Set the master key msk = s , and output the public parameter param : param ={ k , G ₁ , G ₂ , e , q , P , P _pub , H ₁ , H ₂ }, where H ₁ , H ₂ are 2 different hash functions; H ₁ :{0,1} ^* →G ₁ , H ₂ : {0,1} ^* →G ₁ ; A2: Generate a partial private key: This function is executed by the key generation center to generate a partial private key of the server or user; 1) Calculation: Q _S = H ₁ ( ID _S ), Q _R = H ₁ ( ID _R ); 2) Calculate D _S = s∙Q _S , D _R = s∙Q _R ; ₃ ) Send DS and DR _to the server and user respectively; A3: Generate secret value: This function is executed by the server or user to generate another part of the private key of the server or user; 1) The server randomly selects a number x _S ; 2) The user randomly selects a number x _R ; A4: Set private key: This function is executed by the server or user to generate the private key of the server or user; 1) The server sets its own private key as: SK _S ={ SK _{S ,1} , SK _{S ,2} }={ x _S , D _S }; 2) The user sets his own private key as: SK _R ={ SK _{R, 1} , SK _{R ,2} }={ x _R , D _R }; A5: Set public key: This function is executed by the server or user to generate the public key of the server or user; 1) The server sets its own public key as: PK _S = x _S ∙ P; 2) The user sets his own public key as: PK _R = x _R ∙ P ; B. Data encryption stage: Encrypted keywords (SCF-MCLPEKS ⁺ ): This function is executed by the data owner to encrypt keywords; if the data owner wants to send his data to the data user, he can use the following method to set the keyword W To encrypt: 1) For each keyword w _i ∈ W , choose a random number r _i , 2) Calculate Q _R = H ₁ ( ID _R ); 3) Calculate U _i , V _i , K _i as follows: U _i = e ( r _i H ₂ ( w _i ), PK _R )∙ e ( r _i Q _R , P _pub ), V _i = r _i PK _S , K _i = r _i P ; 4) Set the ciphertext as: C ={ C _i }, where C _i ={ U _i , V _i , K _i }; C. Retrieval stage: C1: Generate trapdoor: This function is executed by the data user to generate a trapdoor for retrieval; if the data user wants to retrieve a certain ciphertext with the keyword w , he can generate it according to the following method Trapdoor for retrieval: 1) Calculate and select a random number r ; 2) Set trapdoor T _w as: T _w ={ T ₁ , T ₂ }, where T ₁ , T ₂ are as follows: T ₁ = D _R + x _R ∙ H ₂ ( w ) + rP , T ₂ = rPK _S ; (8) Test: This function is executed by the server to test whether the ciphertext C and the trapdoor T _w match; 1) For each ciphertext C _i ∈ C , calculate U = ( U _i ) ^xS ; 2) Verification: e ( T ₁ , V _i )= U ∙ e ( K _i , T ₂ ); if true, return 1, otherwise, return 0; If w = w _i , then we can get: e ( T ₁ , V _i ) = e ( D _R + x _R ∙ H ₂ ( w ) + rP , r _i PK _S ) = e ( x _R ∙ H ₂ ( w ), r _i PK _S )∙ e ( D _R , r _i PK _S )∙ e ( rP , r _i PK _S ) = e ( r _i ∙ H ₂ ( w ), x _R PK _S )∙ e ( sQ _R , r _i PK _S )∙ e ( r _i P , rPK _S ). = [ e ( r _i ∙ H ₂ ( w ), x _R P )∙ e ( r _i Q _R , sP )] ^xS ∙ e ( K _i , T ₂ ) = ( U _i ) x S ^∙ e ( K _i , T ₂ ).