CN113037732B - Multi-user security encryption de-duplication method based on wide area network scene - Google Patents

Abstract

The invention discloses a multi-user safe encryption de-duplication method based on a wide area network scene.A sending end preprocesses a plaintext message to be sent, and then compares the preprocessed plaintext message with a local cache to replace de-duplication information; the sending end establishes an end-to-end trusted connection to transmit the encrypted processed information to the receiving end; the receiving end receives the encrypted information and decrypts the encrypted information to obtain processed information; the receiving end interactively communicates with the duplicate removal agent of the local area network to obtain the encrypted ciphertext of the information which can be subjected to duplicate removal in a convergence manner, so that the corresponding plaintext information is obtained by decryption, and then the plaintext information is combined with the received information which cannot be subjected to duplicate removal to obtain the original information. And the sending end/the receiving end of the receiving end carries out updating synchronization with the duplicate removal agent of the local area network after each transmission. The method can be applied to encrypted flow, can relieve the transmission pressure of the wide area network, effectively saves the bandwidth of the wide area network, and can ensure the safety and the privacy of user information.

Description

A secure multi-user encryption and deduplication method based on wide area network

technical field

The invention relates to the technical field of redundant traffic elimination in wide area network communication, in particular to a secure encryption and deduplication method based on multiple users in a wide area network scenario.

Background technique

A WAN redundant traffic elimination system involves two or more local area networks connected by WAN links. In such systems, a deduplication agent (eg gateway router) is deployed at the edge of each LAN. Before the information to be sent enters the WAN, the sender cooperates with the local deduplication agent to eliminate redundancy of the information. The sender first divides the information into blocks according to its data characteristics, and then searches for matching blocks in the information to be sent and the information that has been sent. All sent chunks are stored in the deduplication proxy's cache, which can be called a dictionary. The dictionary also stores the fingerprint information corresponding to the block. Then each matchable block in the information is then replaced by the fingerprint information, thereby completing the deduplication processing of the message, thus effectively reducing the amount of data that needs to be transmitted through the WAN. Eliminating redundant or duplicate data in WAN traffic can improve network efficiency and save bandwidth, so for large enterprises, Internet service providers and network equipment vendors, the application value of redundant traffic elimination systems is very large.

Although redundant traffic elimination systems have been successfully deployed on unencrypted traffic, applying them to encrypted traffic and supporting multi-user deduplication remains a great challenge. In particular, existing security transmission protocols such as TLS and IPSec all use end-to-end encryption, which requires that information has been encrypted by the sender before entering the network and can only be decrypted by the receiver after leaving the network. A deduplication proxy in the middle of the sender and receiver only sees encrypted nonsense bytes, there is no way to find matching parts like in unencrypted traffic. In addition, a multi-user deduplication system complicates the task of deduplication agents, since it needs to match not only the information already sent by the sender, but also the historical information of other users.

In addition to the above problems, in the process of information transmission, malicious attackers may also launch poisoning attacks. In a multi-user redundant traffic elimination system, the proxy uses a global cache to perform deduplication, and all users participate in updating and maintaining the cache. A malicious user may insert wrong content in the cache to launch a poisoning attack, and subsequent users will not be able to get the correct content when using the content in the cache to restore the deduplicated information. In fact, there are a large number of users in the local area network, the probability of poisoning attacks is very high, and even if only one user is controlled by a malicious attacker, it will cause system-level harm to all users. A simple idea is that the sender attaches an error detection code to the message so that the receiver can check whether the recovered message is consistent with it. However, this does not solve the poisoning attack, because the tampered content still exists in the proxy's cache and continues to affect subsequent users. The only solution is to clear the tampered content from the proxy cache, which is also very difficult. Specifically, the user needs to convince the proxy that a certain piece of information in the cache has been tampered with without compromising the confidentiality of the information.

SUMMARY OF THE INVENTION

The present invention provides a multi-user secure encryption based on the wide area network scenario in view of the existing in the prior art that duplicate traffic exists in the wide area network transmission, and the current deduplication (RE) systems are all in non-encrypted scenarios. The deduplication method, by realizing cross-user deduplication in an encrypted environment, can effectively achieve message security and reduce bandwidth overhead; in addition, it also enables the system to defend against poisoning attacks by malicious users, which is a problem in existing deduplication methods. It has not been studied in heavy systems.

To achieve the above object, the present invention adopts the following technical solutions:

A multi-user secure encryption and deduplication method based on a wide area network scenario, the encryption and deduplication method comprises the following steps:

S1, for each original text message to be sent, the sender decomposes the original message into an array composed of a certain amount of data blocks according to the data characteristics;

S2, for each data block, the sender calculates the corresponding key and a unique fingerprint for distinguishing different data blocks;

S3, the sender compares the fingerprint of each data block with all the fingerprint information in the local cache, and uses the corresponding key to replace the deduplicated data block;

S4, the sender encrypts the deduplicated data block and sends it to the receiver, and at the same time updates the set of <fingerprint, ciphertext> corresponding to all sent data blocks to the sender's local cache and the sender's local area network deduplication agent;

S5, with the help of the deduplication agent of the local area network of the receiving end, the receiving end obtains the deduplicated data block in combination with the substitute key, fuses the obtained result with the decrypted data block information sent by the transmitting end, and restores the original text information; The set of <fingerprint, ciphertext> corresponding to the sent data block is updated to the deduplication agent of the receiving end and the local area network of the receiving end.

In order to optimize the above technical solutions, the specific measures taken also include:

Further, in step S1, the transmitting end adopts the CDC algorithm to decompose the original information into an array composed of a certain amount of data blocks according to the data characteristics; between the minimum and maximum values.

Further, in step S4, the sending end uploads the set of <fingerprint, ciphertext> corresponding to all the sending data blocks to the deduplication proxy of the local area network of the sending end, and then updates all fingerprint information sets in the deduplication proxy to the local area of the sending end. cache;

Among them, the local cache of the sender only maintains the fingerprint information corresponding to all data blocks sent or received by all users under the local area network where the sender is located through the fingerprint cache table; the deduplication agent of the sender also maintains the aforementioned fingerprint cache table and the corresponding ciphertext table, The ciphertext table stores ciphertexts of data blocks corresponding to all fingerprints in the fingerprint cache table.

Further, in step S5, the receiving end uploads the corresponding <fingerprint, ciphertext> of the received data block to the deduplication proxy of the local area network of the receiving end, and the deduplication proxy of the local area network of the receiving end integrates all fingerprint information sets and will integrate the information. The result is returned to the receiver.

Further, in step S3, the sending end compares the fingerprint of each data block with all the fingerprint information in the local cache, and using the corresponding key to replace the data block that can be deduplicated refers to,

For each data block, the sender searches the fingerprint table in the local cache to check whether the corresponding fingerprint is stored in the fingerprint table; if there is a matching fingerprint, it is determined that the data block has been transmitted, and deduplication is allowed, and step S2 is adopted. The generated key corresponding to the data block replaces the original data block; if there is no matching fingerprint, the original data block is retained.

Further, the receiving end and the sending end are connected by TLS.

Further, in step S5, with the help of the deduplication agent of the local area network of the receiving end, the receiving end obtains the deduplicated data block in combination with the substitute key, and after merging the obtained result with the data block sent by the transmitting end, the original text information is recovered. The process includes the following steps:

S51, the receiving end receives the data block information encrypted by TLS, and decrypts to obtain the key corresponding to the data block after performing deduplication in step S3;

S52, for each deduplicated data block, the receiving end calculates the fingerprint information corresponding to the data block according to the received key, and uploads the calculated fingerprint information to the deduplication agent of the local area network of the receiving end, so that the deduplication of the local area network of the receiving end is performed. The agent returns the ciphertext of the data block corresponding to the fingerprint information to the receiver;

S53, the receiving end performs decryption to obtain the deduplicated data block, replaces the key in the received ciphertext information with the corresponding data block, and restores the original complete information.

Further, the sender uses a convergent encryption algorithm to encrypt the data block.

Further, the encryption and deduplication method also includes the following steps:

S6, the receiving end uses a guard decryption algorithm to detect whether the ciphertext is poisoned, uses a key verification algorithm to confirm whether the current user is an honest user, and removes the poisoned ciphertext.

Further, the encryption and deduplication method also includes the following steps:

The data block is processed based on the MLEvd encryption of the bilinear map e: G ₁ ×G ₂ →G ₃ ; for any symmetric deterministic encryption algorithm SDE=(SK, SE, SD), the following MLEvd algorithm is constructed, where SK is the key Generation algorithm, SE is the encryption algorithm, SD is the decryption algorithm:

A, parameter generation algorithm PG(1 ^λ )→P:

For the input security parameter 1 ^λ , the parameter generation algorithm generates groups G ₁ =<g ₁ >, G ₂ =<g ₂ >, and the order of the group is a prime number p, and their corresponding bilinear mapping is e.

H：{0，1}^*→K为密码学安全的哈希函数，返回的公开参数P包含{e，g₁，g₂，p，H₁，H₂，h，H}；Target group G ₃ ; H ₁ : {0, 1} ^* →G ₁ , H ₂ : {0, 1} ^* →G ₂ , h:

H: {0, 1} ^* → K is a cryptographically secure hash function, and the returned public parameter P includes {e, g ₁ , g ₂ , p, H ₁ , H ₂ , h, H};

B, fingerprint generation algorithm FG(P, m)→F:

For the input plaintext m, the fingerprint

C, the key generation algorithm KG(P, m)→(K(t), t):

输出(K(t)，t)；Sampling a random number t to get the key

output(K(t), t);

D, encryption algorithm ENC(P, m)→C:

Obtain (K(t), t) by calling KG, calculate

c=SE(m, H(K(t)))

Output ciphertext C=(c, T);

E, decryption algorithm DEC(C, K(t))→m':

Calculate the corresponding plaintext m'=SD(c, H(K(t)));

F, the guard decryption algorithm GDEC(C, K(t))→{m', ⊥}:

On the basis of the decryption algorithm, check whether ^Th(m') = K(t), if it does not satisfy the ciphertext problem, return ⊥;

G, the key verification algorithm KV(C, F, K) → {0, 1}:

Check that e(F, T)=e(g ₁ , K), if it returns 1, it means the key is correct, otherwise it returns 0.

The beneficial effects of the present invention are:

(1) The present invention can de-duplicate the traffic of the wide area network under the condition of ensuring data security, which greatly reduces the useless traffic of the network. For poisoning attacks by malicious users, the present invention proposes that MLEvd can support dynamic keys and key verification. Through the new features of MLEvd, the content uploaded by the user is verified to prevent poisoning attacks. This greatly improves the security and reliability of the system.

(2) The present invention reduces the traffic transmitted by the wide area network, can help teams in different regions communicate with each other more quickly, and reduces the occupation of limited wide area networks

Description of drawings

FIG. 1 is a flow chart of a method for secure encryption and deduplication based on multi-users in a wide area network scenario of the present invention.

FIG. 2 is a schematic diagram of a model of one of the application embodiments.

Detailed ways

The present invention will now be described in further detail with reference to the accompanying drawings.

It should be noted that the terms such as "up", "down", "left", "right", "front", "rear", etc. quoted in the invention are only for the convenience of description and clarity, and are not used for Limiting the applicable scope of the present invention, the change or adjustment of the relative relationship shall be regarded as the applicable scope of the present invention without substantially changing the technical content.

In conjunction with Fig. 1, the present invention refers to a secure encryption and deduplication method based on multiple users in a wide area network scenario. The encryption and deduplication method includes the following steps:

S1, for each original text message to be sent, the sender decomposes the original message into an array composed of a certain amount of data blocks according to data characteristics.

In step S1, the transmitting end adopts the CDC algorithm to decompose the original information into an array composed of a certain amount of data blocks according to the data characteristics; the data blocks are divided into blocks based on the content, and the length of each data block is within a defined minimum value. and the maximum value.

S2, for each data block, the sender calculates a corresponding key and a unique fingerprint for distinguishing different data blocks.

The key in step S2 is generated according to the data block, and the fingerprint is a unique identifier of the data block, which can be used to distinguish it from other data blocks. After receiving the key, the receiver can find the ciphertext corresponding to the data block, and then decrypt to obtain the data block.

S3, the sender compares the fingerprint of each data block with all the fingerprint information in the local cache, and uses the corresponding key to replace the deduplicated data block.

The deduplication process in step S3 means that for each data block, the sender searches the fingerprint table in the local cache to check whether the corresponding fingerprint appears in the fingerprint table. If it can be found, it is considered that the data block has been transmitted and can be deduplicated, and then the sender replaces the original data block with the key generated in step S2. If there is no matching fingerprint, the original data block is kept.

S4, the sender encrypts the deduplicated data block and sends it to the receiver, and at the same time updates the set of <fingerprint, ciphertext> corresponding to all sent data blocks to the sender's local cache and the deduplication proxy of the sender's local area network. Here, a trusted connection, such as a TLS connection, is built between the sender and the receiver, which can ensure end-to-end security. The ciphertext here is obtained by encrypting with the key generated in step S2. The encryption algorithm is a convergent encryption algorithm, which is different from the traditional encryption method. The key is generated based on the plaintext information. For the same plaintext information, the encrypted ciphertext is exactly the same.

The updating in step S4 refers to: (1) the sending end maintains a fingerprint cache table, which records the fingerprint information corresponding to all data blocks sent/received by all users under the local area network where the sending end is located; (2) the local go to the sending end. The re-agent maintains a fingerprint cache table and the corresponding ciphertext table, the fingerprint cache table records the fingerprints of the blocks passing through the agent, and the ciphertext table stores the ciphertext of the data blocks corresponding to the fingerprints in the fingerprint cache table.

S5, with the help of the deduplication agent of the local area network of the receiving end, the receiving end obtains the deduplicated data block in combination with the substitute key, fuses the obtained result with the decrypted data block information sent by the transmitting end, and restores the original text information; The set of <fingerprint, ciphertext> corresponding to the sent data block is updated to the deduplication agent of the receiving end and the local area network of the receiving end.

In step S5, the recovery process of the receiving end means that after receiving the TLS-encrypted information, the receiving end first decrypts to obtain the information after performing deduplication in step S3. Next, for the block that can be deduplicated, the receiving end calculates the fingerprint information corresponding to the data block according to the received key, and then uploads the fingerprint information to the local area network deduplication agent. The deduplication agent will return the ciphertext of the data block corresponding to the fingerprint information to the receiver, the receiver will then perform decryption to obtain the corresponding data block, and then replace the key in the information with the corresponding data block, thereby restoring the original complete information.

As one of the preferred examples, the encryption and deduplication method further includes the following steps:

S6, the receiving end uses a guard decryption algorithm to detect whether the ciphertext is poisoned, uses a key verification algorithm to confirm whether the current user is an honest user, and removes the poisoned ciphertext. Specifically, the present invention proposes the DETp protocol to prevent poisoning attacks. After the steps similar to DETs are performed, the poisoning message detection and recovery steps are added, and a guard decryption algorithm is used to detect whether the ciphertext is poisoned. The key verification algorithm is used to confirm that the current user is an honest user and remove the poisoned ciphertext.

A protocol for cross-user deduplication in two encryption environments, including the following steps:

(1) The problem model of cross-WAN encryption and deduplication is extracted, and the adversary model and security are defined.

(2) The DETs deduplication protocol is designed to realize a cross-user protocol encrypted after deduplication.

(3) The message locked encryption is optimized, and it is proposed that MLEvd can further support dynamic keys and key verification.

(4) The DETp deduplication protocol is designed to prevent poisoning attacks by malicious users.

The problem model is shown in Fig. 2. The present invention considers the situation that a company has two branches in different cities, and can also be extended to multiple branches. Each branch has its own local area network (LAN) to connect internal users (users). For example, the left branch has a user Alice, and the right branch has a user Bob. At the same time the two branches are connected by a public wide area network (WAN). An agent resides on the gateway node in each branch and assists the user nodes of both LANs to perform deduplication on their WAN traffic. For example, the agent of the branch on the left is Carol, and the agent of the branch on the right is David.

The invention proposes a DETs deduplication protocol, which includes dividing the message into blocks, using a single-item hash function satisfying cryptographic security to generate the fingerprint and encryption key corresponding to the message block, judging whether the message block is repeated according to the fingerprint, and then dividing the repeated message block. Perform deduplication, end-to-end secure transmission based on TLS, recovery of deduplicated messages after receiving messages, and synchronization of messages between users and agents.

的MLEvd加密。对于任意一个对称确定加密算法SDE＝(SK，SE，SD)，其中SK是密钥生成算法，SE是加密算法，SD是解密算法，本发明可以构建以下七步MLEvd算法：In addition, the present invention proposes a bilinear map based on e:

MLEvd encryption. For any symmetrically determined encryption algorithm SDE=(SK, SE, SD), where SK is a key generation algorithm, SE is an encryption algorithm, and SD is a decryption algorithm, the present invention can construct the following seven-step MLEvd algorithm:

A, parameter generation algorithm PG(1 ^λ )→P:

For the input security parameter 1 ^λ , the parameter generation algorithm generates a group G ₁ =<g ₁ >, G ₂ =<g ₂ >, and the order of the group is a prime number p, and their corresponding bilinear mapping is e;

H：{0，1}^*→K为密码学安全的哈希函数，返回的公开参数P包含{e，g₁，g₂，p，H₁，H₂，h，H}；Target group G ₃ ; H ₁ : {0, 1} ^* → G ₁ , H ₂ : {0, 1} ^★* → G ₂ , h:

H: {0, 1} ^* → K is a cryptographically secure hash function, and the returned public parameter P includes {e, g ₁ , g ₂ , p, H ₁ , H ₂ , h, H};

B, fingerprint generation algorithm FG(P, m)→F:

For the input plaintext m, the fingerprint

C, the key generation algorithm KG(P, m)→(K(t), t):

输出(K(t)，t)；Sampling a random number t to get the key

output(K(t), t);

D, encryption algorithm ENC(P, m)→C:

Obtain (K(t), t) by calling KG, calculate

c=SE(m, H(K(t)))

Output ciphertext C=(c, T);

E, decryption algorithm DEC(C, K(t))→m':

Calculate the corresponding plaintext m'=SD(c, H(K(t)));

F, the guard decryption algorithm GDEC(C, K(t))→{m', ⊥}:

On the basis of the decryption algorithm, check whether ^Th(m') = K(t), if it does not satisfy the ciphertext problem, return ⊥;

G, the key verification algorithm KV(C, F, K) → {0, 1}:

Check that e(F, T)=e(g ₁ , K), if it returns 1, it means the key is correct, otherwise it returns 0.

As shown in Figure 1, the present invention considers the situation that a company has two branches in different cities, and can also be extended to multiple branches. Each branch has its own local area network (LAN) to connect internal users (users). At the same time the two branches are connected by a public wide area network (WAN). An agent resides on the gateway node in each branch and assists the user nodes of both LANs to perform deduplication on their WAN traffic. For security reasons, users communicate over TLS connections, which provide admirable end-to-end security. Users and agents work together to securely run the DTEs (DTEp) protocol, enabling deduplication over encrypted connections.

The DTEs protocol proposed by the present invention includes the following steps:

1. Block: For each piece of information M sent by Alice, Alice runs the CDC block algorithm to divide M into a series of information blocks:

M={m ₁ , m ₂ , . . . , m _n }.

2. Generate keys and fingerprints: For each information block m _i , Alice computes its key using

K _i =h(m _i )

and fingerprints

F _i =h(K _i )

where h is a single-item hash function that satisfies cryptographic security.

3. Deduplication: For each information block, Alice goes to the local fingerprint database T _La to check whether the fingerprint of this information block exists. If it exists, it means that this information block has been sent and can be de-duplicated. When sending, only the key needs to be sent instead of the complete information block. This can greatly reduce communication. With this key, the recipient can find the correct ciphertext and decrypt the file. After deduplication, Alice sends information M'={m ₁ ', m ₂ ',..., m _n '}, where m _i ' is:

4. End-to-end transmission: Alice and Bob establish a TLS connection, and then Alice sends M' to Bob through the connection. The TLS connection guarantees that only Bob can see the message.

5. Message recovery: After Bob receives the message M', he needs to recover the message with the help of David. David here is the deduplication proxy for Bob's LAN. The specific details are as follows. For each K _i in M', Bob calculates its fingerprint F _i , and at the same time goes to David to download the encrypted message block c _i corresponding to the fingerprint. Bob then decrypts:

m _i =DEC( _{ci ,K i )}

At the same time, each _Ki in M' is replaced by _mi , thus restoring M.

Alice使用K_i加密m_i得到6.Alice synchronization: for each

Alice uses K _i to encrypt m _i to get

c _i =ENC(m _i ,K _i )

Alice sends all <F _i , c _i > to Carol, her local area network agent. At the same time, Alice downloads the global fingerprint table T _Gc from Carol and updates her local fingerprint table T _La .

7. Carol synchronization: After receiving <Fi _{, c i >} , Carol inserts them into the global fingerprint table T _Gc and synchronizes the latest global fingerprint table to Alice.

8. Bob synchronization: For each received, Bob calculates and encrypts it, Bob calculates at the same time, and sends all to his local LAN agent David. At the same time, Bob downloads the global fingerprint table from David and updates his local fingerprint table.

9. David synchronization: After receiving <Fi _{, c i >} , David inserts them into the global fingerprint table T _Gd and synchronizes the latest global fingerprint table to Bob.

Under the DTEs protocol, the user can upload the wrong encrypted message block, so that the receiver can obtain the wrong information. In order to prevent this situation, the present invention further proposes DTEp. The details of the protocol are as follows:

1. Block: For each piece of information M sent by Alice, Alice runs the CDC block algorithm to divide M into a series of information blocks:

M={m ₁ , m ₂ , . . . , m _n }.

2. Generate keys and fingerprints: In order to achieve efficient query operations, DETp uses certain fingerprints

For the key used for encryption and decryption, the present invention achieves that David can verify whether the key and the fingerprint match, while he cannot know how to calculate the key from the fingerprint. For this purpose, the keys are:

3. Deduplication: For each information block, Alice goes to the local fingerprint database T _La to check whether the fingerprint of this information block exists. Unlike DTEs, for repeated message blocks, we send their hash value h(m _i ). After deduplication, Alice sends information M'={m ₁ ', m ₂ ',..., m _n '}, where m _i ' is:

4. End-to-end transmission: Alice and Bob establish a TLS connection, and then Alice sends M' to Bob through the connection. The TLS connection guarantees that only Bob can see the message.

5. Message recovery: After Bob receives the message M', he needs to recover the message with the help of David. The specific details are as follows. For each h(m _i ) in M', Bob calculates its fingerprint F _i and key K _i (t), and at the same time goes to David to download the encrypted message block C _i ( t). Because it supports dynamic keys, the ciphertext of DETp needs to add a nonce that can only be used once:

C _i (t)=( _ci (t), T)

in:

c _i =ENC(m _i ,K _i (t))

After obtaining the ciphertext C _i (t), Bob calculates the key:

K _i (t)=(T) ^h(m) .

Then decrypt _ci (t) to get the plaintext:

m _i =DEC( _{ci (t),K i (} t)).

Finally, to ensure that the recovered message is correct, Bob can _compute the fingerprint of the recovered message mi and compare it to the fingerprint he received from Alice. If both are the same, the message is correct. Otherwise, the recovered message is false, and Bob needs to request Alice to send the correct message, which cannot be the hash value sent after deduplication.

Alice使用K_i加密m_i得到c_i，同时生成一个随机数t，计算T，得到密文C_i(t)。6.Alice synchronization: for each

Alice uses K _i to encrypt m _i to obtain c _i , generates a random number t at the same time, calculates T, and obtains the ciphertext C _i (t).

Alice sends all <F _i , C _i (t)> to Carol, her local area network agent. At the same time, Alice downloads the global fingerprint table T _Gc from Carol and updates her local fingerprint table T _La .

7. Carol synchronization: After receiving <F _i , C _i (t)>, Carol inserts them into the global fingerprint table T _Gc and synchronizes the latest global fingerprint table to Alice.

8. Bob synchronization: for each received _{mi, Bob calculates K i and} encrypts _mi to get C _i (t), Bob calculates F _i at the same time, and sends all <F _i ,C _i (t)> to him Where the LAN agent David. At the same time, Bob downloads the global fingerprint table T _Gd from David and updates his local fingerprint table T _Lb .

9. David synchronization: After receiving <F _i , C _i (t)>, David inserts them into the global fingerprint table T _Gd , and synchronizes the latest global fingerprint table to Bob.

10. Detect and correct poisoned data: If Bob sees the ciphertext being _poisoned , he needs to submit the correct <Fi, _Ki (t)>.

David check

e(F _i , T)=e(g ₁ , K _i (t))

If satisfied, David considers K _i (t) to be the correct key, and he will check the ciphertext in his hand. The verification method is the same as Bob. If the ciphertext is wrong, he will use the correct ciphertext for Bob to synchronize.

The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions that belong to the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (8)

1. a multi-user security based deduplication method based on a wide area network scenario, is characterized in that, the encryption deduplication method comprises the following steps: S1, for each original text message to be sent, the sender decomposes the original message into an array composed of a certain amount of data blocks according to the data characteristics; S2, for each data block, the sender calculates the corresponding key and a unique fingerprint for distinguishing different data blocks; S3, the sender compares the fingerprint of each data block with all the fingerprint information in the local cache, and uses the corresponding key to replace the deduplicated data block; S4, the sender encrypts the deduplicated data block and sends it to the receiver, and at the same time updates the set of <fingerprint, ciphertext> corresponding to all sent data blocks to the sender's local cache and the sender's local area network deduplication agent; S5, with the help of the deduplication agent of the local area network of the receiving end, the receiving end obtains the deduplicated data block in combination with the substitute key, fuses the obtained result with the decrypted data block information sent by the transmitting end, and restores the original text information; The set of <fingerprint, ciphertext> corresponding to the sent data block is updated to the deduplication agent of the receiving end and the local area network of the receiving end. 2. the multi-user security encryption and deduplication method based on the wide area network scenario according to claim 1, is characterized in that, in step S1, described sending end adopts CDC algorithm to decompose original information into a certain amount according to data characteristic An array of data blocks; the data blocks are divided into blocks based on content, and the length of each data block is between a defined minimum value and a maximum value. 3. the multi-user's secure encryption and deduplication method based on the wide area network scenario according to claim 1, is characterized in that, in step S4, described sending end uploads the corresponding <fingerprint, ciphertext> set of all sending data blocks To the deduplication agent of the local area network of the sender, and then update all fingerprint information sets in the deduplication agent to the local cache of the sender; Among them, the local cache of the sender only maintains the fingerprint information corresponding to all data blocks sent or received by all users under the local area network where the sender is located through the fingerprint cache table; the deduplication agent of the sender also maintains the aforementioned fingerprint cache table and the corresponding ciphertext table, The ciphertext table stores ciphertexts of data blocks corresponding to all fingerprints in the fingerprint cache table. 4. the multi-user security-based encryption deduplication method according to claim 1, is characterized in that, in step S5, described receiver will receive the corresponding <fingerprint, ciphertext> of the data block Upload it to the deduplication agent of the local area network of the receiving end, and the deduplication agent of the local area network of the receiving end integrates all fingerprint information sets and returns the integration result to the receiving end. 5. the encryption and deduplication method based on the security of multi-users under the wide area network scenario according to claim 1, it is characterized in that, in step S3, described sending end will the fingerprint of each data block and all fingerprints in the local cache The information is compared, and the corresponding key is used to replace the data block that can be deduplicated. For each data block, the sender searches the fingerprint table in the local cache to check whether the corresponding fingerprint is stored in the fingerprint table; if there is a matching fingerprint, it is determined that the data block has been transmitted, and deduplication is allowed, and step S2 is adopted. The generated key corresponding to the data block replaces the original data block; if there is no matching fingerprint, the original data block is retained. 6 . The secure encryption and deduplication method based on multiple users in a wide area network scenario according to claim 1 , wherein the receiving end and the sending end are connected by TLS. 7 . 7. the multi-user security-based deduplication method according to claim 1, is characterized in that, in step S5, described by the deduplication agent of the local area network of the receiving end, the receiving end obtains in conjunction with the substitute key After deduplicating the data block, the process of recovering the original text information includes the following steps: S51, the receiving end receives the data block information encrypted by TLS, and decrypts to obtain the key corresponding to the data block after performing deduplication in step S3; S52, for each deduplicated data block, the receiving end calculates the fingerprint information corresponding to the data block according to the received key, and uploads the calculated fingerprint information to the deduplication agent of the local area network of the receiving end, so that the deduplication of the local area network of the receiving end is performed. The agent returns the ciphertext of the data block corresponding to the fingerprint information to the receiver; S53, the receiving end performs decryption to obtain the deduplicated data block, replaces the key in the received ciphertext information with the corresponding data block, and restores the original complete information. 8. The secure encryption and deduplication method based on multi-users in a wide area network scenario according to claim 1, wherein the encryption and deduplication method further comprises the following steps: The receiving end uses the guard decryption algorithm to detect whether the ciphertext is poisoned, uses the key verification algorithm to confirm whether the current user is an honest user, and removes the poisoned ciphertext, specifically: The data block is processed based on MLEvd encryption of bilinear mapping e: G ₁ ×G ₂ →G ₃ ; for any symmetric deterministic encryption algorithm SDE=(SK, SE, SD), the following MLEvd algorithm is constructed, where SK is the key Generation algorithm, SE is the encryption algorithm, SD is the decryption algorithm: A, parameter generation algorithm PG(1 ^λ )→P: For the input security parameter 1 ^λ , the parameter generation algorithm generates a group G ₁ =<g ₁ >, G ₂ =<g ₂ >, and the order of the group is a prime number p, and their corresponding bilinear mapping is e; Target group G ₃ ; H ₁ :{0,1} ^* →G ₁ ,H ₂ :{0,1} ^★* →G ₂ ,

H:{0,1} ^* →K is a cryptographically secure hash function, and the returned public parameter P includes {e,g ₁ ,g ₂ ,p,H ₁ ,H ₂ ,h,H}; B, the fingerprint generation algorithm FG(P,m)→F: For the input plaintext m, the fingerprint

C, the key generation algorithm KG(P,m)→(K(t),t): Sampling a random number t to get the key

output(K(t),t); D, encryption algorithm ENC(P,m)→C: Obtain (K(t), t) by calling KG, calculate c=SE(m,H(K(t)))

Output ciphertext C=(c, T); E, decryption algorithm DEC(C,K(t))→m': Calculate the corresponding plaintext m'=SD(c,H(K(t))); F, the guard decryption algorithm GDEC(C,K(t))→{m',⊥}: On the basis of the decryption algorithm, check whether ^Th(m') = K(t), if it does not satisfy the ciphertext problem, return ⊥; G, the key verification algorithm KV(C,F,K)→{0,1}: Check that e(F,T)=e(g ₁ ,K), if it returns 1, it means the key is correct, otherwise it returns 0.

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