WO2019223310A1 - Digital crime scene investigation record trusted model system - Google Patents

Abstract

Disclosed in the present invention are a digital crime scene investigation record trusted model system and a method for performing a trusted operation using the system. The system records a digital crime scene investigation record trusted model as T, wherein T=(E,A,DR,TR,Sign), TR is a trusted digital crime scene investigation record set, TR={tr _i|tr _i＝dr _i+Sign(dr _i)}, and Sign is a trusted operation. If the recorded data above is tampered with, a verification failure would be caused, and trusted crime scene investigation data tr _n can be verified. The present invention is targeted at digital records generated in crime scene investigation, and can perform a trusted operation on the digital records to generate trusted crime scene investigation digital records. The credibility of the records is reflected in tamper resistance and non-repudiation. Since a terminal is specially used by a special person, the digital signature makes it clear which terminal the data comes from. Thus, the terminal holder cannot deny the fact. The present invention effectively solves the existing technical problem of easily tampering with photos and videos captured by mobile terminals, and solves the problem of how to add a signature later and sign on behalf.

Description

Trusted model system of digital survey record Technical field

The invention belongs to the technical field of protecting data integrity in digital data processing, and particularly relates to a trusted model system for digital field survey records.

Background technique

With the advancement of science and technology, various police work of the public security department has also entered the digital era. Crime scene investigation usually refers to the scene where investigators, in order to ascertain the facts of the crime, collect the evidence of the crime, and expose the corroborated criminals, according to law, on the people and events related to the crime, as well as places, objects, people, and corpses. For visits, investigations and inspections, crime scene investigations must be conducted in specific space areas in accordance with national laws and regulations, using criminal scientific and technological means. The current survey record is a collection of documents and attachments formed after the site survey is completed. It mainly includes: field transcripts, photos, videos, audio, traces, various physical evidence, electronic data evidence, and drawings. Among these current survey records, photos, videos, and audio have been digitally collected. The current survey records in the form of transcripts, drawings, etc. are manually entered into the on-site survey information system by the surveyors to realize digitization.

Site investigation is a highly procedural task. Any small flaw in the workflow will lead to serious consequences, such as insufficient evidence collection and damage to trace evidence. Among them, the failure of the credibility of the current survey records is a catastrophic result, which will cause the starting point of the entire evidence chain not to be adopted, thereby rendering the entire current survey work invalid. The existing credibility mechanism of current survey records is based on "signature". Each paper-based survey record and trace physical evidence collection list must be signed by the investigator to ensure the credibility of the record. In order to prevent the record from being tampered with, generally Requires signature of more than two investigators. However, in the actual site survey, there are many problems with the "signature" specification, which are mainly reflected in the following two points: 1. The signature is supplemented, and some investigators did not promptly request Records and checklists are signed and re-signed afterwards; Second, on behalf of the signatures, some investigators did not participate in the on-site investigation and signed for or on behalf of others for procedural needs.

Any of the above acts will cause the credibility of the current investigation records to be questioned, which will lay hidden dangers for subsequent judicial certification work. In the digital age, even if the risks of manual signatures mentioned above are circumvented, how to effectively ensure their credibility is an important issue that needs to be solved in the face of a large number of digital current survey records.

In the existing patent documents, the invention with the application number CN201710140360.5 and the name "a method and system for fixing electronic evidence on the spot" discloses a method and system for fixing electronic evidence on the spot. The method includes obtaining user login information, selecting user rights, and starting recording user operations; collecting on-site electronic evidence; stopping recording of user operations, and generating a recording result of a user operation log; performing integrity verification on the obtained electronic evidence; Generate electronic reports of electronic evidence, and add the integrity verification results of electronic evidence to electronic reports; upload electronic files, the above through the user login module, evidence collection module, integrity verification result module, report generation module and upload module All modules are implemented together. Although the present invention solves the technical problem that the photos and videos taken by the existing mobile terminal are easy to be tampered to some extent, it still does not solve the problems of signature supplement and signature replacement.

Summary of the Invention

In view of the above problems in the prior art, the present invention proposes a digital reconnaissance record trusted model system. By using methods such as digital signatures and hashing in cryptography, the digital reconnaissance records can be trusted Operation to ensure that all digital survey information from the beginning of the record to the submission of the court, the recorded content, the person who recorded, the location, the recording time and other digital information is complete and has not been tampered with.

In order to achieve the above object, the technical solution adopted by the present invention is a digital reconnaissance record trusted model system, which records the digital reconnaissance record trusted model as T, T = (E, A, DR, TR, Sign) Among them, E is an entity in the model, E = {S, C _i }, S is a server, C _i is a terminal for current survey, S and C _i are connected through a wireless communication network, and A is a trusted model. A set of cryptographic algorithms. Server S uses the asymmetric encryption algorithm in A to generate public and private keys. DR is a collection of all digital survey records. DR = {dr _i | dr _i ∈ {digital photo, digital record, video, audio}} The information of DR is stored in _Ci , TR is a set of trusted digital reconnaissance records, TR = {tr _i | tr _i = dr _i + Sign (dr _i )}, Sign is a credible operation, and the credibility operation using the above private key, the date and time DT are input to the server S, GPS coordinate information of the current location C _i input to C _i.

Further, the above-mentioned on-site survey terminal equipment C _{i is} bound to the identity of the investigator using the equipment, and is dedicated to a specific person.

Preferably, the above-mentioned survey terminal device C _{i is} equipped with a high-definition camera, a GPS sensor, Wi-fi and 4G signal access capabilities.

Further, the aforementioned cryptographic algorithm set includes an asymmetric key pair generation algorithm, a symmetric key algorithm, a signature algorithm, and a hash algorithm.

The invention further proposes a method for performing credible operation by using the above-mentioned digital reconnaissance record trusted model system, which specifically includes the following steps:

First, the initialization process

Use the RSA algorithm to generate the public and private keys for the server S, recorded as PK _s and SK _s . PK _{s is} stored in the digital certificate, recorded as Cert _s . SK _s applies the AES algorithm (AES, Advanced Encryption Standard) and strong encryption. The key is stored locally on server S;

Second, the registration process

Registration needs to be completed before using the surveying terminal equipment for the first time. The server issues a certificate for the surveying terminal equipment and sends the private key to the terminal in an encrypted manner. All the surveying terminal equipment and the public key of the server are stored on the server and Publicly accessible

Third, the signature process

1. Site survey terminal equipment C _i collects site survey data dr _n through the equipment;

2. The survey terminal device C _i obtains the geographic location coordinates of the survey data collected through its own GPS sensor, and records it as G _n ;

3. Now survey terminal C _i trusted timestamp request to a server;

4. The server returns the current time dt _n to the current survey terminal device, and adds a digital signature to ensure the credibility of the time. The reply content is: Timestamp _n = dt _n + Sign (SK _s , dt _n );

5. The field survey terminal equipment C _i verifies the credibility of the time, and performs credible processing on the field survey data dr _n as follows to obtain the credible field survey data tr _n :

Further, the above-described registration process comprises: _i inspect the site terminal device C transmits a registration request to the server S _i and Key, which is the password holder is provided its own terminal i, the server generates the key pair S _i is C

E and D are the encryption and decryption functions of the symmetric encryption algorithm AES, Sign uses the asymmetric cryptographic algorithm DSA (Digital Signature Algorithm) for signing, and H is the hash function of the SHA1 (Secure Hash Algorithm) algorithm.

Further, the survey data described in step 3 of the signature process may be text, pictures, audio, and video.

If the recorded data is tampered with, the verification will fail. The process of verifying the trusted spot survey data tr _n is as follows:

S1: decompose tr _n into two parts of original data O and verification data V, O = dr _n + G _n + TimeStamp _n ,

Where TimeStamp _n = dt _n + Sign (SK _s , dt _n ),

O = dr _n + G _n + dt _n + Sign (SK _s , dt _n );

S2: Verify that the timestamp in the original data O is valid, and check whether the following equation holds:

dt _n = Validate (PK _s , Sign (SK _s , dt _n ))

If it is true, continue to the next step; if it is not true, it will prompt the verification failure and abort the verification process;

S3: Verify the authenticity of the original data O, and check whether the following equation holds:

If it is true, it means that the verification is successful; if it is not true, it indicates that the verification has failed;

S4: The verification process ends.

Compared with the prior art, the present invention has the following beneficial technical effects:

1. According to the present invention, a digital record generated during a crime scene investigation is credibly processed to generate a credible current investigation digital record. The record contains the current investigation data, the collection place, the collection time, and the person's information. information.

2. The trusted record uses the terminal's private key to sign the record, and the person who collected the record saves the record. The credibility of the record is reflected in tamper resistance and non-repudiation, because the terminal is dedicated and the digital signature ensures that the data is collected The terminal owner cannot deny which terminal.

3. If the survey record is tampered, it will be found through the verification process, that is, if the recorded data is tampered, the verification will fail, which not only effectively solves the technical problem that the photos and videos taken by the existing mobile terminal are easy to be tampered with. , And solved the problem of how to prevent supplemental signatures and sub-signatures.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a structural diagram of a trusted model of digital survey records.

FIG. 2 is a flowchart of terminal registration.

Figure 3 is a flow chart of the credibility verification of the survey data.

Detailed ways

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

Figure 1 depicts the structure of a trusted model. The present invention refers to the trusted model of digital reconnaissance records as T, T = (E, A, DR, TR, Sign), where E is an entity in the model, E = {S, C _i }, S is the server, and C _i is the surveying terminal equipment, S and _Ci are connected through a wireless communication network; A is the set of cryptographic algorithms in the model; DR is the collection of all digital surveying records,

DR = {dr _i | dr _i ∈ {digital photo, digital transcript, video, audio}}; TR is a trusted set of digital current survey records, TR = {Sign (dr _i )}; Sign is a credible operation; DT is the date and time; GPS is the current geographic location coordinate of C _i .

The process of using this system for trusted operations is as follows:

(A) initialization process

Use the RSA algorithm to generate the public and private keys for the server S, recorded as PK _s and SK _s . PK _{s is} stored in the digital certificate, recorded as Cert _s . SKs uses the AES algorithm and a strong key stored locally on the server.

(B) the registration process

Figure 2 is a flowchart of terminal registration. The terminal equipment C _i is the hand-held device of the reconnaissance personnel. The equipment is equipped with high-definition cameras, GPS sensors, Wi-fi and 4G signal access capabilities, and input functions. The identities of one investigator are bound one by one, and they are used exclusively by one person. This registration process needs to be completed before using the terminal device for the first time.

In FIG. 2, Key _i is a password set by the holder of terminal i. The purpose is to protect the security of the private key. E and D are the encryption and decryption functions of the symmetric encryption algorithm AES in cryptography, Sign uses the asymmetric cryptography algorithm DSA for signature, and H is the hash function of the SHA1 algorithm. The purpose of this step is to let the server issue a certificate for the terminal and send the private key to the terminal in an encrypted manner. All public keys of the terminal and server are kept on the server and can be accessed publicly.

(Three) the signature process

3.1. The terminal C _i collects the current survey data dr _n through the equipment, and the data can be text, pictures, audio, and video;

3.2. The terminal C _i obtains the geographic location coordinates of the collected survey data through its own GPS sensor, and records it as G _n ;

3.3, request a trusted timestamp from the server;

3.4. The server returns the current time dtn to the terminal and adds a digital signature to ensure the credibility of the time. The reply content is: Timestamp _n = dt _n + Sign (SK _s , dt _n )

3.5. The terminal Ci verifies the credibility of the time and performs credible processing on the survey data drn as follows to obtain the trusted survey data tr _n :

Figure 3 is a flowchart of the credibility verification of the survey data, which describes the whole process of trn verification of a trusted survey record. If the recorded data is tampered, the verification will fail.

To facilitate those skilled in the art to implement the present invention, a specific embodiment is provided:

Assume that the server S has completed the initialization operation, PK _s has been made public, and SK _s has been kept secret; another investigator A is equipped with a site survey terminal C bound to A's identity and the server has generated it A public-private key pair, the public key PK _c has been made public, and SK _c has been kept secret on the terminal C.

Suppose investigator A obtains a computer hard disk at the crime scene and uses his own current survey terminal equipment C to take pictures and evidence of this physical evidence. The digital photo file name of the physical evidence is DC0017.JPG. While the picture is being saved, the terminal equipment collects it. The geographic position value on its own GPS sensor is G = (lat: 22.5024, lng: 113.9383), and after sending a trusted time stamp request to the server S, the server returns the current trusted time stamp. Timestamp is dt = "2018-03 -10 18:09:22 "and the server's signature Sign (PK _s , dt).

The terminal device uses the public key of the server certificate to decrypt Sign (PK _s , dt) to verify the credibility of dt. If it is true and valid, it generates the trusted spot survey data tr by the following steps:

1. Calculate the SHA1 hash value of DC0017.JPG: H (DC0017.JPG);

Step 2. The obtained hash value is 1 and G Timestatmp combined, and the terminal using a private key SK _S arithmetic _{sign: Sign (SK s, H (} DC0017.JPG), G, Timestamp);

3. The final credible field survey data tr is a combination of the following data:

DC0017.JPG, G, Timestamp, Sign (SK _s , H (DC0017.JPG), G, dt)

Next, the trusted verification process for tr is as follows:

1. First divide tr into the original data part O: DC0017.JPG, G, Timestam and verification data part V: Sign (SK _s , H (DC0017.JPG), G, dt);

2. Use the server's public key to verify the credibility of Timestamp in the original data, check whether dt is equal to Validate (PK _s , Sign (PK _s , dt)), if they are equal, it means that the timestamp is credible, and continue to the next verification; Otherwise, the verification process is aborted, and the verification fails;

3. Perform SHA1 hash operation on DC0017.JPG of the original data part of tr and combine it with dt of G and Timestamp to form the following data: H (DC0017.jpg) + G + dt, recorded as O ';

4. Use the server's public key to unlock the verification data part of tr, that is, Validate (PK _s , V), and then check whether O 'is equal to Validate (PK _s , V). If they are not equal, it will prompt verification failure, if they are equal, then verify Success, the physical evidence photo DC0017.JPG is credible, that is, the collection time of the physical evidence photo is 2018-03-10 18:09:22, and the latitude and longitude coordinates of the collection place are (latitude: 22.5024, longitude: 113.9383),

The collection was conducted by investigator A. No tampering was found in the photo content. The above information is true and valid.

According to the present invention, a digital record generated during the investigation of a crime scene is credibly processed to generate a credible digital record of the current investigation. The record contains information of the current investigation data, the collection location, the collection time, and the collection person. And guarantee that this information cannot be tampered with, and at the same time non-repudiation.

It should be noted that the description of the above specific embodiments is not intended to limit the present invention, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. .

Claims (8)

1. A digital reconnaissance record trusted model system, characterized in that the system records the digital reconnaissance record trusted model as T, T = (E, A, DR, TR, Sign), where E is the model Entity, E = {S, C _i }, S is the server, C _i is the current survey terminal equipment, S and C _i are connected through a wireless communication network, A is the set of cryptographic algorithms in the trusted model, and server S uses A The asymmetric encryption algorithm generates public and private keys. DR is a collection of all digital survey records, DR = {dr _i | dr _i ∈ {digital photo, digital transcript, video, audio}}, and DR information is stored in C _i Here, TR is a set of trusted digital on-site survey records, TR = {tr _i | tr _i = dr _i + Sign (dr _i )}, Sign is a credible operation, which uses the above private key , date and time DT are input to the server S, GPS coordinate information of the current location C _i input to C _i.
2. The digital on-site survey record trusted model system according to claim 1, wherein the on-site survey terminal equipment C _{i is} bound to the identity of the investigator using the equipment.
3. The digital reconnaissance record trusted model system according to claim 2, characterized in that said reconnaissance terminal equipment _{Ci is} equipped with a high-definition camera, a GPS sensor, Wi-fi and 4G signal access capabilities.
4. The digital on-site record trusted model system according to claim 1, wherein the cryptographic algorithm set includes an asymmetric key pair generation algorithm, a symmetric key algorithm, a signature algorithm, and a hash algorithm.
5. A method for performing credible operation by using a trusted model system of digital on-site survey records according to claim 1, comprising the following steps:

   (A) initialization process

   Use the RSA algorithm to generate the public and private keys for the server S, recorded as PK _s and SK _s . PK _{s is} stored in the digital certificate, recorded as Cert _s and made public. SK _{s is} stored locally on the server S using the AES algorithm and a strong key;

   (B) the registration process

   Registration needs to be completed before using the surveying terminal equipment for the first time. The server issues a certificate for the surveying terminal equipment and sends the private key to the terminal in an encrypted manner. All the surveying terminal equipment and the public key of the server are stored on the server and Publicly accessible

   (Three) the signature process

   a) Site survey terminal equipment C _i collects site survey data dr _n through the equipment;

   b) The survey terminal device C _i obtains the geographic location coordinates of the survey data collected through its own GPS sensor, and records it as G _n ;

   c) inspect the site terminal C _i trusted timestamp request to a server;

   d) The server returns the current time dt _n to the current survey terminal equipment, and adds a digital signature to ensure the credibility of the time. The reply content is: TimeStamp _n = dt _n + Sign (SK _s , dt _n );

   e) The current survey terminal equipment C _i verifies the credibility of the time, and performs credible processing on the survey data dr _n as follows to obtain the trusted survey data tr _n :

   f) tr _n = (dr _n + G _n + TimeStamp _n ) + Sign (SK _ci , (H (dr _n ) + G _n + dt _n )).
6. The method according to claim 5 for performing credible operations using a trusted model system of digital survey records, characterized in that the registration process specifically comprises: the survey terminal device C sends a registration request and K _i to the server S, the latter being holder password terminal C _i of the self-setting, the server S generates a key pair of C _i

   

   E and D are the encryption and decryption functions of the symmetric encryption algorithm AES, Sign uses the asymmetric cryptographic algorithm DSA for signature, Validate uses DSA for signature verification, and H is the hash function of the SHA1 algorithm.
7. The method according to claim 5 for performing credible operations using a trusted model system of digital survey records, wherein the data in step a of the signature process may be text, pictures, audio, or video.
8. The method for performing credible operation by using a trusted model system of digital survey records according to claim 5, characterized in that the process of verifying the trusted survey data tr _n is as follows:

   S1: decompose tr _n into two parts of original data O and verification data V, O = dr _n + G _n + TimeStamp _n ,

   

   

   Among them, TimeStamp _n = dt _n + Sign (SK _s , dt _n ), O = dr _n + G _n + dt _n + Sign (SK _s , dt _n );

   S2: Verify that the timestamp in the original data O is valid, and check whether the following equation holds:

   dt _n = Validate (PK _s , Sign (SK _s , dt _n ))

   If it is true, continue to the next step; if it is not true, it will prompt the verification failure and abort the verification process;

   S3: Verify the authenticity of the original data O, and check whether the following equation holds:

   

   If it is true, it means that the verification is successful; if it is not true, it indicates that the verification has failed;

   S4: The verification process ends.

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