A method and system for encrypted chain auditing of privacy computing platforms

Abstract

This invention discloses a method and system for encrypted chain auditing of a privacy computing platform, relating to the field of information security technology. The method includes: generating current log content based on operations performed on a target file and dividing it into multiple levels; encrypting the level content based on corresponding level keys to obtain corresponding level encrypted content; calculating and signing hash values ​​based on the original encrypted content of the target file and the current log content to obtain an initial log signature and a current log signature; performing hash calculations based on the level encrypted content, the original encrypted content, the initial log signature, the current log signature, and related timestamps to obtain a log chain; adding the log chain to the target file to form a file log structure; decrypting the log content in the log chain based on the access user level; and performing risk auditing based on the log chain. While ensuring the traceability of data file usage, this method achieves access permission isolation for different roles when accessing log content, ensuring the integrity of log data.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of information security, and more particularly to a ciphertext chain audit method and system for a privacy computing platform. BACKGROUND

[0002] With data elements rising as important resources, how to realize efficient circulation and collaborative use of data under the premise of guaranteeing data privacy and compliance safety has become a key issue for the development of digital economy. Privacy computing technology emerges as the times require, relying on advanced cryptography and system security means such as multi-party secure computing, homomorphic encryption, federated learning, and trusted execution environment, breaking through the problem of privacy leakage and data abuse caused by traditional "centralized data and centralized computing", and realizing a new mode of fusion analysis of "data available but invisible". However, while supporting cross-institutional data collaboration, the privacy computing platform also introduces higher-dimensional compliance challenges - under the premise of "data invisibility", how to ensure that the behavior of each party is controlled, the operation is left with traces, and the responsibility is traceable, highlighting the core position and great value of the audit mechanism in the privacy computing platform.

[0003] The current common audit methods include: database audit, and blockchain audit. The traditional database audit mechanism relies on a centralized database to add, back up and retrieve operation records, has certain management and query efficiency, but has the following defects: high tampering risk: the records are usually maintained by the platform itself, if the system permission is broken or the internal personnel tamper maliciously, the audit records can be modified quietly; weak credibility: lacking strong encryption mechanism and chain structure, it is difficult for the third party to verify the integrity of the data records; lack of anti-repudiation: the operation subject may deny the behavior, and the log cannot be used as evidence with legal effect. The limitations of blockchain audit The operation record is uploaded to the chain, which can improve the credibility and anti-tampering, but in the privacy computing platform, the blockchain audit also faces some problems: large performance overhead: on-chain operations need consensus verification, broadcast synchronization, and the writing speed is much lower than local storage, which is difficult to support high-frequency audit scenarios; insufficient scalability: the blockchain is naturally limited by throughput and storage space, and it is difficult to support fine-grained, high-frequency, and cross-domain audit data; privacy exposure risk: the characteristics of the blockchain require data transparency, but the privacy computing scenario requires "operation verifiable but not visible", which is contradictory to the goal; high deployment cost: building a consortium chain or private chain requires introducing complex infrastructure such as consensus mechanism, node governance, and on-chain contract, which requires a large amount of engineering investment. In comparison, the chain log is more practical and has technical advantages in the privacy computing scenario. The chain log audit uses a hash chain structure to encrypt and link each operation record, so that if any record is tampered with, the hash of all subsequent records will be invalid. However, in the privacy computing scenario and other scenarios that require high data isolation, integrity, and verifiability, the log and the target file exist independently. If they are mismatched or tampered with, the verification chain will be broken and the integrity will be compromised. Once offline or transferred across platforms, it is difficult to independently verify the security status of the file and the operation record.

[0004] Therefore, how to realize the traceability of data file use in the privacy computing platform and the permission isolation of different role personnel accessing log content, and further protect the integrity of log data is a problem that those skilled in the art need to solve. SUMMARY

[0005] Therefore, the present application provides a ciphertext chain audit method and system for a privacy computing platform, which realizes the permission isolation of different role personnel accessing log content and further protects the integrity of log data.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] A ciphertext chain audit method for a privacy computing platform, comprising:

[0008] Generating current log content based on the target file performing operation and dividing it into multiple levels of content;

[0009] encrypting the level content based on the corresponding level key, to obtain corresponding level encrypted content;

[0010] calculating hash values and signing based on the original encrypted content of the target file and the current log content, to obtain initial log signature and current log signature correspondingly;

[0011] calculating hash values based on the level encrypted content, the original encrypted content, the initial log signature, the current log signature and related time stamps, to obtain initial log hash value and current log hash value together forming a log chain;

[0012] adding the log chain to the target file to form a file log structure;

[0013] decrypting the log content in the log chain based on the level of the access user;

[0014] conducting risk audit based on the log chain.

[0015] In one embodiment, the level content acquisition method is:

[0016] dividing the current log content into high-sensitivity content, medium-sensitivity content and low-sensitivity content based on the sensitivity of business operation;

[0017] the high-sensitivity content, the medium-sensitivity content and the low-sensitivity content together as the level content;

[0018] the high-sensitivity content includes core fields and original content summaries of operation data;

[0019] the medium-sensitivity content includes operator type, impact range and behavior summary;

[0020] the low-sensitivity content includes log unique identifier and operator identifier.

[0021] In one embodiment, the level encrypted content acquisition method is:

[0022] obtaining high-level key, medium-level key and low-level key;

[0023] encrypting the high-sensitivity content based on the high-level key, to obtain high-level encrypted data;

[0024] encrypting the medium-sensitivity content based on the medium-level key, to obtain medium-level encrypted data;

[0025] encrypting the low-sensitivity content based on the low-level key, to obtain low-level encrypted data;

[0026] the high-level encrypted data, the medium-level encrypted data and the low-level encrypted data together form the level encrypted content.

[0027] In one embodiment, the current log signature acquisition method is:

[0028] The log content generated by each operation before the current log content is obtained as the historical log content;

[0029] Based on the historical log content and the current log content, a hash calculation is performed to obtain a current hash value;

[0030] Based on the private key of the operator, the current hash value is signed to obtain the current log signature.

[0031] In one embodiment, the log chain acquisition method is:

[0032] Based on the level encrypted content, the original encrypted content, the initial log signature and the initial timestamp, a hash calculation is performed to obtain the initial log hash value;

[0033] Based on the level encrypted content, the current log signature, the initial log hash value or the hash log generated by the previous operation, and the current timestamp, a hash calculation is performed to obtain the current log hash value;

[0034] Based on the initial log hash value and the current log hash value, a link is formed to form the log chain;

[0035] The initial timestamp and the current timestamp together constitute the related timestamp.

[0036] In one embodiment, the current log hash value specifically includes:

[0037] Based on the target file, the initial log hash value is generated by performing the first operation;

[0038] Based on the target file, a second log hash value is generated by performing the second operation;

[0039] In this way, all log hash values generated by performing two or more operations on the target file are sorted according to the number of operations and linked together as the current log hash value.

[0040] In one embodiment, the log content in the log chain is decrypted based on the access user level, specifically including:

[0041] Based on the access user, identity and permission verification is performed;

[0042] If the verification fails, the access request is rejected;

[0043] If the verification passes, the corresponding access log level and access log are determined based on the level of the access user and the request.

[0044] obtaining a corresponding level key based on the access log level;

[0045] verifying validity of the log hash of the access log based on a verification rule;

[0046] if the verification passes, decrypting the access log based on the level key, recording log access behavior to an access audit log and adding to the end of the file log structure;

[0047] if the verification fails, reporting data misplacement information and tracing to find a malicious user.

[0048] In one embodiment, risk auditing is performed based on the log chain, specifically including:

[0049] structure integrity verification, signature validity verification and access consistency verification are respectively performed based on the log chain;

[0050] The structure integrity verification specifically includes verifying the hash values in the log chain piece by piece to confirm that the log hash has not been deleted, modified or inserted;

[0051] The signature validity verification specifically includes signature legality verification based on all signature ciphers in the log chain;

[0052] The access consistency verification specifically includes comparison and verification of the access behavior of the access user and the access audit log to determine whether there is illegal access, tampering or forgery;

[0053] When the above verifications all pass, the audit passes;

[0054] Otherwise, the audit fails and a punishment mechanism is triggered.

[0055] In one embodiment, the punishment mechanism is:

[0056] terminating the related program, broadcasting risk problems to other users through the platform and finding the malicious user;

[0057] corresponding to the malicious level of the malicious user, increasing the access threshold, joining the blacklist, deducting the reputation score or legal accountability.

[0058] A ciphertext chain audit system for a privacy computing platform, comprising: a log content division module, a division content encryption module, a ciphertext signature module, a file log generation module, a log access module and a risk audit module;

[0059] The log content division module is configured to generate current log content based on a target file performing an operation and divide the log content into multiple level contents;

[0060] The division content encryption module is configured to encrypt the level content based on the corresponding level key to obtain corresponding level encrypted content.

[0061] The ciphertext signature module is configured to perform hash value calculation and signature based on the original encrypted content of the target file and the current log content, to obtain an initial log signature and a current log signature.

[0062] The file log generation module is configured to perform hash calculation based on the level encrypted content, the original encrypted content, the initial log signature, the current log signature and related time stamps, to obtain an initial log hash value and a current log hash value, which together form a log chain; and based on the log chain, the target file is formed into a file log structure.

[0063] The log access module is configured to decrypt the log content in the log chain based on the level of an access user.

[0064] The risk audit module is configured to perform risk audit based on the log chain.

[0065] According to the above technical solution, compared with the prior art, the present application provides a ciphertext chain audit method and system for a privacy computing platform, which has the following beneficial effects:

[0066] 1. Trusted audit system is included: the log chain is encapsulated with the target file, does not need to rely on the platform database or external system, and uses embedding to verify the integrity and operation history, and is suitable for cross-institution and cross-data domain circulation scenarios.

[0067] 2. Anti-tampering enhancement: each chain is linked through forward hash, log encryption and ciphertext signature structure, and any attempt to tamper with or delete nodes will cause the whole chain to fail, in addition, through encryption (such as CP-ABE, KP-ABE), even if the third-party attacker is stolen, it is also difficult to analyze the content.

[0068] 3. Easy to archive, transmit and supervise: the target file and its complete audit track are "integratedly stored", the supervisory party can directly decrypt and verify the chain audit structure during the transmission process of the target file, and the data credibility and compliance visibility are improved.

[0069] 4. Support integrated verification: the chain structure is designed as an embedded "section" or "tail block" (such as an encrypted chain section appended at the end of the file), which can support incremental writing, regular snapshot audit encryption, form a timeline complete computing behavior log, support binding with data digest, and facilitate verification of the consistency of the whole file. BRIEF DESCRIPTION OF DRAWINGS

[0070] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0071] Figure 1 The present invention provides a flowchart of a ciphertext chain auditing method for a privacy computing platform.

[0072] Figure 2 The flowchart illustrates the method for decrypting log content in a log chain based on access user level, as provided by this invention.

[0073] Figure 3 This invention provides a schematic diagram of a ciphertext chain auditing system for a privacy computing platform. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0075] Example 1

[0076] like Figure 1 As shown, this embodiment of the invention discloses a method for encrypted chain auditing for a privacy computing platform, including the following steps, which are numbered S1 to S7 for ease of description:

[0077] S1 performs operations based on the target file to generate the current log content and divides it into multiple levels of content;

[0078] S2 encrypts the level content based on the corresponding level key to obtain the corresponding level encrypted content;

[0079] S3 calculates and signs the hash value based on the original encrypted content of the target file and the current log content, thus obtaining the initial log signature and the current log signature.

[0080] S4 performs hash calculations based on the level of encrypted content, the original encrypted content, the initial log signature, the current log signature, and the relevant timestamps, and obtains the initial log hash value and the current log hash value, which together form a log chain.

[0081] S5 adds target files based on log chains to form a file log structure;

[0082] S6 decrypts the log content in the log chain based on the access user level;

[0083] S7 performs risk audit based on the log chain.

[0084] The application adopts an integrated chain log data structure, divides the content, encrypts using different keys, then embeds the chain audit log ciphertext in the target file, supports access to encrypted content according to permissions, and if a malicious user is found, a punishment mechanism will be triggered, further increasing the security.

[0085] Based on the chain log audit self-embedding, hierarchical encryption, digest signature and access, the permission isolation problem of different role personnel accessing log content is solved.

[0086] Further, in S1, generating the current log content specifically includes:

[0087] Based on the operation record of the user or platform role on the target file each time, the corresponding log content is formed as the current log content; wherein, the operation is specifically adding, deleting, modifying and querying the data in the target file.

[0088] Further, in S1, the log content generated by the first operation on the target file is the initial log content, and the log content generated by the second and subsequent operations is represented as the second log content, the third log content, etc. Since the subsequent processing methods of each log content are the same and in order to facilitate representation, the initial log content, the second log content, the third log content, etc. are uniformly represented as the current log content.

[0089] Further, in this embodiment, the i-th log content is represented as:

[0090] {

[0091] "log_id": "UUIDv4", / / Unique identification

[0092] "prev_hash": H i-1 , / / Hash value of the previous log (in the first log, the value is the hash value of the original encrypted content of the target file)

[0093] “hash” : H i , / / Record the hash value of this log

[0094] "timestamp": T i , / / Precise timestamp (with time zone)

[0095] "user_id": U i , / / Operator identification

[0096] "Type": A i , / / Operator identifier

[0097] "Details": { / / Hierarchical data area (core)

[0098] "H": High-sensitive operation details, H-level key encryption

[0099] "M": Medium ordinary operation details, M-level key encryption

[0100] "L": Low-risk information, L-level key

[0101] },

[0102] "Signature": Sig(Hash(Z i )) / / System or user private key signature

[0103] }。

[0104] Further, in S1, the plurality of level content acquisition methods are:

[0105] Based on the sensitivity of the business operation, the current log content is divided into high-sensitive content , medium-sensitive content and low-sensitive content ;

[0106] High-sensitive content, medium-sensitive content and low-sensitive content are collectively used as level content;

[0107] High-sensitive content includes: core field and original content summary of operation data;

[0108] Medium-sensitive content includes: operator type, impact range and behavior summary;

[0109] Low-sensitive content includes: log unique identifier and operator identifier.

[0110] Further, in S2, the level encryption content acquisition method is:

[0111] Get high-level key K H , medium-level key K M and low-level key K L ;

[0112] Based on the high-level key K H , encrypt the high-sensitive content to get high-level encrypted data :

[0113] ;

[0114] Based on the medium-level key K MSensitive content Intermediate encryption data is obtained by encrypting :

[0115] ;

[0116] Based on the low-level key K L Sensitive content Low-level encryption data is obtained by encrypting :

[0117] ;

[0118] The high-level encryption data, the intermediate encryption data and the low-level encryption data together constitute the level-encrypted content.

[0119] Further, in S2, the high-level key K H , the intermediate key K M and the low-level key K L are centrally hosted by a key management system (KMS), authorized and distributed according to user roles, responsible for key generation, storage, update and recovery; the key management system (KMS) generates independent keys for each level according to the content level of the log:

[0120] ;

[0121] Wherein, K u represents the final available key combination of the user, k represents a single key, Permission represents a permission determination function (return value is 0 or 1), R u represents user attributes.

[0122] Further, in S2, different levels of content are implemented by KP-ABE (Key-Policy ABE) for efficient encryption, and a digital signature mechanism can be integrated to ensure source verification.

[0123] Further, in S3, the initial log signature acquisition method is:

[0124] Hash calculation is performed based on the original encrypted content CC1 of the target file to obtain an initial hash digest Z1:

[0125] Z1=Hash(CC1);

[0126] The initial hash digest Z1 is signed based on the private key of the operator to obtain the initial log signature Sig1:

[0127] Sig1=sig(Z1);

[0128] Wherein, sig represents a signature algorithm.

[0129] Further, in S3, the current log signature obtaining method is:

[0130] The log content generated by each operation before the current log content is obtained as the historical log content CC i , i≥2:

[0131] CC i =RZ1+RZ2+...+RZ i-1 ;

[0132] Wherein, RZ i-1 represents the log content generated by the i-1th operation before the current log content;

[0133] Based on the historical log content CC i and the current log content RZ i , a hash calculation is performed to obtain the current hash value Z i ;

[0134] Z i =Hash(CC i +RZ i )

[0135] Based on the private key of the operator, the current hash value Z i is signed to obtain the current log signature Sig i :

[0136] Sig i =sig(Z i )。

[0137] Further, in S3, the Hash algorithm adopts MD5 or SHA256.

[0138] Further, in S4, the log chain obtaining method is:

[0139] Based on the level encrypted content, the original encrypted content CC1, the initial log signature Sig1 and the initial timestamp T1, a hash calculation is performed to obtain the initial log hash value H1;

[0140] Based on the level encrypted content, the current log signature Sig i , the initial log hash value H1 or the hash log H i-1 generated by the previous several times and the current timestamp T i , a hash calculation is performed to obtain the current log hash value H i ;

[0141] Based on the initial log hash value H1 and the current log hash value H i , a link is formed to form a log chain;

[0142] The initial timestamp T1 and the current timestamp Ti Together they form the relevant timestamp.

[0143] Furthermore, the current log hash value specifically includes:

[0144] The initial log hash value is generated based on the first operation performed on the target file.

[0145] The second operation is performed on the target file to generate a second log hash value;

[0146] Similarly, all log hash values ​​generated by performing operations on the target file two or more times are linked together according to the number of executions and used as the current log hash value.

[0147] Furthermore, the initial log hash value H1 is specifically:

[0148] ;

[0149] in, Z1 represents the initial high-sensitivity content generated during the first operation on the target file. Initial sensitive content and initial low-sensitivity content The initial high-level encrypted data, initial medium-level encrypted data, and initial low-level encrypted data obtained after encryption are respectively, with || representing the concatenation operator.

[0150] Furthermore, since there is no previous log entry before the initial log, in order to maintain the integrity of the chained log, the hash value Z1=Hash(CC1) of the original encrypted content of the target file is added to the initial log instead of the hash value of the previous log entry.

[0151] The second log hash value H2 is specifically:

[0152] ;

[0153] Where T2 represents the timestamp of the second operation on the target file. Z1 represents the initial log content generated by the second operation on the target file, which is divided into the second high-sensitivity content. Second sensitive content Second low-sensitivity content The resulting high-level encrypted data, medium-level encrypted data, and low-level encrypted data are obtained after encryption.

[0154] Furthermore, the current log hash value H generated by the i-th operation on the target file. i Specifically:

[0155] ;

[0156] wherein, H i-2 represents the log hash generated by the i-2th operation on the target file, H i-1 represents the log hash generated by the i-1th operation on the target file.

[0157] Further, based on the initial log hash value H1 and all other log hashes H i linking, forming a log chain, forming a continuous hash chain, ensuring the integrity of the log chain structure.

[0158] Further, in S5, the log chain is appended to the tail of the target file, forming an encapsulated structure, that is, an integrated file log structure.

[0159] When a user attempts to tamper with a record, the hash value will change, thus identifying the malicious user; when attempting to delete a log, the attacker cannot forge the user's signature of the ciphertext digest, thus causing the hash chain to break; when a user attempts to write an incorrect log, the malicious behavior can be traced due to the existence of the signature, date, etc. Therefore, the log security in the case of malicious writing, tampering, and deletion by attackers is ensured, and the mechanism ensures strong binding between the log and the original data, improving data integrity and audit convenience.

[0160] Further, in S6, as shown in Figure 2 the log content in the log chain is decrypted based on the access user level, specifically including:

[0161] Identity and permission verification based on the access user;

[0162] If the verification fails, the access request is rejected;

[0163] If the verification passes, the corresponding access log level and access log are determined based on the access user level and request;

[0164] The corresponding level key is obtained based on the access log level;

[0165] The validity of the log hash of the access log is verified based on the verification rule;

[0166] If the verification passes, the access log is decrypted based on the level key, the log access behavior is recorded to the access audit log, and the file log structure is added to the end of the file log structure;

[0167] If the verification fails, the data misplacement information is reported and the malicious user is traced.

[0168] This mechanism ensures that the log is still under complete control during use, preventing unauthorized disclosure of information.

[0169] Further, if the visitor can only view L and M level logs, the KMS sends the corresponding level key K after identity and permission verification of the access user is passed M and K L .

[0170] Further, the log access behavior includes: visitor, access time, visitor level, and request source.

[0171] Further, in S7, risk auditing is performed based on the log chain, specifically including:

[0172] Structural integrity verification, signature validity verification, and access consistency verification are performed based on the log chain respectively;

[0173] The structural integrity verification specifically includes: verifying the hash value in the log chain piece by piece to confirm that the log hash has not been deleted, modified, or inserted;

[0174] The signature validity verification specifically includes: signature legality verification based on all signature ciphertexts in the log chain;

[0175] The access consistency verification specifically includes: comparing and verifying the access behavior of the access user with the access audit log to determine whether there is illegal access, tampering, or forgery behavior;

[0176] When the above verifications are all passed, the audit is passed;

[0177] Otherwise, the audit is not passed and a punishment mechanism is triggered.

[0178] Further, the signature legality verification specifically includes:

[0179] Suppose the system is operated and the private key generated by the system is used for signature, and when verifying, only the corresponding public key is used for verification, and if an error occurs, it is considered to be a modified log.

[0180] Further, the risk auditing can periodically or on-demand integrity scanning and behavior auditing, automatically identify potential risks, and if it is found that the log is tampered with, the malicious user will be found, so that punishment measures are implemented to avoid greater losses in the future.

[0181] Further, the punishment mechanism is:

[0182] Terminating the related program, broadcasting the risk problem to other users through the platform, and finding the malicious user;

[0183] Based on the malicious level of the malicious user, the following is performed: increasing the access threshold, joining the blacklist, deducting the reputation score, or legal accountability.

[0184] Embodiment 2

[0185] Based on the same inventive concept, asFigure 3 The application also provides a ciphertext chain audit system for a privacy computing platform, which comprises a log content division module, a division content encryption module, a ciphertext signature module, a file log generation module, a log access module and a risk audit module.

[0186] The log content division module is configured to generate current log content based on the operation performed on the target file and divide the current log content into multiple levels of content.

[0187] The division content encryption module is configured to encrypt the levels of content based on corresponding levels of encryption keys to obtain corresponding levels of encrypted content.

[0188] The ciphertext signature module is configured to perform hash value calculation and signature based on the original encrypted content of the target file and the current log content, and obtain an initial log signature and a current log signature.

[0189] The file log generation module is configured to perform hash calculation based on the levels of encrypted content, the original encrypted content, the initial log signature, the current log signature and related time stamps, and obtain an initial log hash value and a current log hash value to jointly form a log chain.

[0190] The log access module is configured to decrypt the log content in the log chain based on the access user level.

[0191] The risk audit module is configured to perform risk audit based on the log chain.

[0192] Preferably, in the embodiment, the function implementation methods of the functional modules correspond to the above methods one by one, and will not be described one by one here.

[0193] Embodiment 3

[0194] Based on the same inventive concept, the application also provides a computer device, which comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory complete communication with each other through the communication bus.

[0195] The memory is configured to store a computer program.

[0196] The processor is configured to execute the program stored on the memory, and can realize the ciphertext chain audit method for the privacy computing platform in the embodiment 1.

[0197] The electronic device may include a processor, a communications interface, memory, and a communication bus, wherein the processor, communications interface, and memory communicate with each other via the communication bus. The processor can invoke logical instructions in the memory to execute a ciphertext chaining auditing method for a privacy computing platform as described in Embodiment 1.

[0198] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0199] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0200] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for encrypted chain auditing of a privacy computing platform, characterized in that, The method comprises the following steps: generating current log content based on target file operation and dividing the current log content into multiple levels of content; encrypting the levels of content based on corresponding level keys to obtain corresponding level encrypted content; calculating hash values based on original encrypted content of the target file and the current log content and signing to obtain initial log signature and current log signature; calculating hash values based on the level encrypted content, the original encrypted content, the initial log signature, the current log signature and related time stamps to obtain initial log hash value and current log hash value to form a log chain; the log chain acquisition method comprises the following steps: calculating hash values based on the level encrypted content, the original encrypted content, the initial log signature and initial time stamp to obtain the initial log hash value; calculating hash values based on the level encrypted content, the current log signature, the initial log hash value and current time stamp to obtain the current log hash value; or calculating hash values based on the level encrypted content, the current log signature, previously generated log hash values and current time stamp to obtain the current log hash value; linking the initial log hash value and the current log hash value to form the log chain; the initial time stamp and the current time stamp jointly form the related time stamp; adding the log chain to the target file to form a file log structure; decrypting log content in the log chain based on access user level; performing risk audit based on the log chain.

2. The method of claim 1, wherein, The multiple levels of content acquisition method comprises the following steps: dividing the current log content into high-sensitivity content, medium-sensitivity content and low-sensitivity content based on sensitivity of business operation; the high-sensitivity content, the medium-sensitivity content and the low-sensitivity content jointly form the levels of content; the high-sensitivity content comprises core fields and original content summaries of operation data; the medium-sensitivity content comprises operator type, influence range and behavior summary; the low-sensitivity content comprises log unique identifier and operator identifier.

3. The method of claim 2, wherein, The level encrypted content acquisition method comprises the following steps: obtaining high-level key, medium-level key and low-level key; encrypting the high-sensitivity content based on the high-level key to obtain high-level encrypted data; encrypting the medium-sensitivity content based on the medium-level key to obtain medium-level encrypted data; encrypting the low-sensitivity content based on the low-level key to obtain low-level encrypted data; the high-level encrypted data, the medium-level encrypted data and the low-level encrypted data jointly form the level encrypted content.

4. The method of claim 1, wherein, The current log signature acquisition method comprises the following steps: obtaining log content generated by each operation before the current log content as historical log content; calculating hash values based on the historical log content and the current log content to obtain current hash value; signing the current hash value based on private key of the operator to obtain the current log signature.

5. The method of claim 1, wherein, The current log hash value specifically comprises: generating the initial log hash value based on first operation on the target file; generating second log hash value based on second operation on the target file; Similarly, all log hash values generated by the target file performing two or more operations are sorted according to the number of operations and linked together as the current log hash value.

6. The method of claim 3, wherein, Decrypt the log content in the log chain based on the access user level, specifically including: Perform identity and permission verification based on the access user; If the verification fails, the access request is rejected; If the verification passes, determine the corresponding access log level and access log based on the level of the access user and the request; Obtain the corresponding level key based on the access log level; Verify the validity of the log hash of the access log based on the verification rule; If the verification passes, decrypt the access log based on the level key, record the log access behavior to the access audit log, and add it to the end of the file log structure; If the verification fails, report the data misplacement information and trace the malicious user.

7. The method of claim 6, wherein, Risk audit based on the log chain, specifically including: Respectively perform structure integrity verification, signature validity verification, and access consistency verification based on the log chain; The structure integrity verification specifically verifies the hash values in the log chain one by one to confirm that the log hash has not been deleted, modified, or inserted; The signature validity verification specifically verifies the signature legality based on all signature ciphertexts in the log chain; The access consistency verification specifically compares and verifies the access behavior of the access user with the access audit log to determine whether there is illegal access, tampering, or forgery; If all the above verifications pass, the audit passes; Otherwise, the audit fails and triggers a punishment mechanism.

8. The method of claim 7, wherein, The punishment mechanism is: Terminate the related program, broadcast the risk problem to other users through the platform, and find the malicious user; Based on the malicious level of the malicious user, perform: increase the access threshold, join the blacklist, deduct reputation points, or legal accountability.

9. A ciphertext chain-based auditing system for a privacy computing platform, configured to perform a ciphertext chain-based auditing method for a privacy computing platform according to any one of claims 1-8, characterized in that, It includes: Log content division module, division content encryption module, ciphertext signature module, file log generation module, log access module, and risk audit module; The log content division module is used to generate current log content based on the target file performing operations and divide it into multiple level contents; The division content encryption module is used to encrypt the level contents based on the corresponding level keys to obtain corresponding level encrypted contents; The ciphertext signature module calculates and signs the hash values based on the original encrypted content of the target file and the current log content, corresponding to the initial log signature and the current log signature; The file log generation module is used to calculate the hash values based on the level encrypted contents, the original encrypted content, the initial log signature, the current log signature, and the related time stamps, corresponding to the initial log hash value and the current log hash value, to form a log chain; based on the log chain, add the target file to form a file log structure; The log access module is used to decrypt the log content in the log chain based on the access user level; The risk audit module is used to perform risk audit based on the log chain.

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