CN107395355A - A kind of cloud storage data integrity verification method based on implicit trusted third party - Google Patents

Abstract

Current data integrity verification method both domestic and external is broadly divided into two classes according to function：Support private checking and support open checking.The former computing cost is low than the latter, but because data verification person's itself is insincere, is not particularly suited for the data verification scene of reality；In actual applications, because the data volume for being stored in cloud service is huge, the verification efficiency of the latter becomes more and more lower with the increase of data volume, causes practicality not high.The present invention proposes a kind of cloud storage data integrity verification method based on implicit trusted third party.Method is verified framework and shown by implicit trusted third party distorts the open checking of daily record realization, reduces the online demand of user to greatest extent.Complete to verify using ECC AESs, efficiency can be improved than existing other method, the realizability of open checking is improved while guaranteed efficiency.

Description

A kind of cloud storage data integrity verification method based on implicit trusted third party

Technical field

The present invention relates to cloud storage technical field, more particularly to a kind of verification method of cloud storage data integrity.

Background technology

Along with the extensive use of cloud storage technology, threat caused by the data safety of Cloud Server is stored in increasingly Cause the concern of people.When data storage be related to enterprise's sensitive data (the Hospital medical business that is included in such as electronic health record or Financial situation) or during individual privacy information (the patients' privacy illness included in such as electronic health record), how to ensure the complete of data Property is particularly important.

Current data integrity verification method both domestic and external is broadly divided into two classes according to function：Support private checking and support Open checking.The former computing cost is low than the latter, but because data verification person's itself is insincere, is not particularly suited for The data verification scene of reality.The latter introduces trusted third party (trusted third party, abbreviation TTP) checking data, will AES is combined with Bilinear map technology so that TTP completes to verify and return result in the case where that can not obtain data User.But because it is related to efficient e computings in Bilinear map computing, therefore the computing cost of the latter is far longer than the former.In reality In the application of border, the data volume due to being stored in cloud service is huge, and the verification efficiency of the latter becomes with the increase of data volume Must be more and more lower, cause practicality not high.

The content of the invention

In view of the deficienciess of the prior art, the present invention proposes that a kind of cloud storage data based on implicit trusted third party are complete Integrity verification method, computing cost is reduced while open authentication function is realized.

A kind of cloud storage data integrity verification method based on implicit trusted third party, its technical method is divided into following several Individual part：

(1) introduce PKI mechanism, respectively data integrity validation module (data integrity verify, DIV) and User generates a pair of RSA keys：(dpk, dsk) and (upk, usk)；

(2) user's selection key is data encryption using ECC AESs, calculates label, utilizes DIV dpk to encrypt private Key；

(3) DIV initiates to challenge to CSP when verifying, server calculates data evidence and returned as requested after accepting challenges Experimental evidence；

(4) DIV experimental evidences generate corresponding checking journal entry according to result, are sent to CSP and write daily record by CSP.

Brief description of the drawings

Fig. 1 is tripartite's interaction of implicit trusted third party's checking framework；

Fig. 2 is checking business process map；

Fig. 3 is the aobvious checking log chain for distorting daily record.

Embodiment

Implicit trusted third party's checking framework, tripartite's interaction of implicit trusted third party's checking framework are as shown in Figure 1.

Verification method based on ECC：

It is assumed that λ is security parameter, h and f are pseudo-random function (PRF), and per is pseudo-random permutation (PRP), and H is Hash letter Number.We input security parameter λ and l to pseudo-random function and pseudo-random permutation function.h:{ 0,1 }^*→ { 0,1 }^m

(1) initialization process

PKI mechanism is introduced, respectively DIV and User generate a pair of RSA keys：(dpk, dsk) and (upk, usk), by text Part m points are isometric n blocks, { m₁, m₂...m_n}。

KeyGen(1^λ) → (pk, sk):

1. user chooses one and is defined on domain F_qOn elliptic curve E (F_q), take a littleAs on the curve Basic point；

2. and then for given security parameter λ (herein referring to key length), d is chosen as private key sk, P (x, y)=d G (x, y) is used as public key pk.

3. user utilizes DIV upk encryption keys d.

(2) label is produced

TagGen (pk, sk, m) → T_m

1. user selectsAs coefficient, i is the unique index of each blocks of files here；

2. calculate kG (x, y) and T using public key_i=kP (x, y)+m_i+h(i)；

3. output label T_iAnd G₀(x, y)=kG (x, y), and send it to Cloud Server.

(3) generation challenge

During checking, DIV initiates challenge Q=(c, k to server₁, k₂), k₁, k₂The number randomly selected, respectively as with Machine permutation function per and pseudo-random function f key, for allowing server to calculate sample block coefficient i_jWith coefficient correlation α_j, c is The quantity of challenge data block.

(4) generation proves

GenProof (pk, F, Q) → T_m

After DIV challenges to server, server can calculate corresponding proof, note F=(m according to challenge₁, m₂… m_n) and T=(T₁, T₂…T_n)。

1. for 1≤j≤c, server calculates the corresponding coefficient for the block being sampled

2. calculateLabel proves

And

3. outputAnd send it to proofs of the DIV as challenge-response.

(5) checking proves

VeriProof (pk, sk, Q, ρ) → { success, " failure " }

1. user calculatesDraw and sampled Block sequence number and coefficient of correspondence；

2. calculate

3. checkingWhether set up, if then exporting " success ", otherwise export " failure ".

Verify daily record

Verify that daily record generates audit log according to data integrity inspection result by DIV and examined by DIV according to the data property held The fruit that comes to an end generates, the structured record (Fig. 3) being stored on magnetic disk media.Journal entry (log entry, abbreviation LE) is basis One journal entry of the property held inspection result generation, a log chain will be formed corresponding to all journal entries of same file group Table.User is by having access to the daily record chained list of file, you can checks the property the held audit history of this document.LE is made up of 5 fields, Wherein, result is the result of this property held inspection, as a result represents that file is intact for 1, is as a result damaged for 0 expression file； Time is the time of daily record generation, for ensureing the freshness and non-reproduction of journal entry；Eid be journal entry in cloud only One mark；Prev_eid is once journal entry identifies corresponding to audit before identical file, for forming daily record chained list；Sig is DIV Utilize RSA signatures of its private key dsk to result, time, eid and prev_eid together.

Item quotes (entry reference, abbreviation ER) and corresponds uniquely to a file, is made up of 5 fields, its In, UID is the identity of user, and GID is the mark of this document, and the two is unique in cloud；Eid is a journal entry mark Know；Time is the timestamp that ER is created or modified；Sig is RSA signatures of the DIV using its private key dsk to preceding 4 fields；ER Journal entry LE caused by always being audited with the newest once property held of this document has identical eid. after file is created, DIV generates the file that a corresponding ER did not audit, i.e., without corresponding journal entry, its ER.eid is 1, and ER.sig is sky.

DIV realization

It is proposed that realize implicit DIV with anti-tamper (tamper-resistant) reliable hardware with following properties： Other entities can not change its internal processes and state, it is impossible to obtain its key information；Attacked when detecting for the physics of oneself When hitting, DIV should be able to perform self to secret information and destroy.Existing security coprocessor product such as IBM 4764 [17], can be with Meet DIV above-mentioned functional requirement.Due to DIV deployment beyond the clouds, SSP should ensure that DIV normal work, not by from the external world Attack.Therefore, whether daily record chained list is imperfect caused by DIV self is destroyed or user data is damaged, and all judges Associated responsibilities are not fulfiled for DIV.

DIV and CSP interaction protocol

Assuming that successful deployment, each side can smoothly obtain the public key of other party to PKI, interaction protocol given here only relates to And data integrity validation flow is as shown in Figure 2.CSP periodically sends checking request to DIV, and each cycle is represented with epoch. After DIV receives checking request, generation challenge is initiated to challenge to CSP.CSP calculates evidence P according to the challenge that receives, and by its together with The ER of this document group sends jointly to DIV.If this document is to receive audit for the first time, it is NULL, LE.prev_ to put ER.eid Eid is NULL.After DIV receives evidence and ER, ER freshness and the true and false (by time and sig domains) are verified, is verified, then New journal entry LE is generated, by the result write-in wherein, and updates ER time and sig domains.LE is returned to together with ER CSP, by its write verification daily record.

The specific embodiment of the present invention is described above.It is to be appreciated that the invention is not limited in above-mentioned Particular implementation, those skilled in the art can make various deformations or amendments within the scope of the claims, this not shadow Ring the substantive content of the present invention.

Claims (5)

1. A kind of 1. cloud storage data integrity verification method based on implicit trusted third party, it is characterised in that：Including following step Suddenly：D) PKI mechanism, respectively data integrity validation module (data integrity verify, DIV) and User lifes are introduced RSA keys in a pair：(dpk, dsk) and (upk, usk)；

   2) user's selection key is data encryption using ECC AESs, calculates label, utilizes DIV dpk encryption key；

   3) DIV initiates to challenge to CSP when verifying, server calculates data evidence after accepting challenges and returns to checking card as requested According to；

   4) DIV experimental evidences generate corresponding checking journal entry according to result, are sent to CSP and write daily record by CSP.
2. 2. a kind of cloud storage data integrity verification method based on implicit trusted third party according to claim 1, its It is characterised by：It is that data integrity validation module (data integrity verify, DIV) and User are generated using PKI mechanism A pair of RSA keys：(dpk, dsk) and (upk, usk), key decryption corresponding data need to be utilized during subsequent authentication.
3. 3. a kind of cloud storage data integrity verification method based on implicit trusted third party according to claim 1, its It is characterised by：It is data encryption using ECC AESs, calculates label, and send into CSP, is encrypted using DIV dpk private Key is simultaneously sent to DIV.
4. 4. a kind of cloud storage data integrity verification method based on implicit trusted third party according to claim 1, its It is characterised by：DIV initiates to challenge to CSP during checking, challenge set Q=(c, k₁, k₂), server is as requested after accepting challenges Calculate data evidence and return to experimental evidence, k₁, k₂It is the number randomly selected, c is the quantity of challenge data block.
5. 5. a kind of cloud storage data integrity verification method based on implicit trusted third party according to claim 1, its It is characterised by：DIV and using itself key dsk decryption acquisition user's key and using the key experimental evidence generated according to result Corresponding checking journal entry, is sent to CSP and writes daily record by CSP.