KR102175806B1 - Method for providing contents certification in social media service and, server, user device and application implementing the method - Google Patents

Abstract

A method in which a server providing a social media service verifies the contents of a conversation, the step of receiving a request input in a chat room from a first participant terminal using the social media service, and sending a first message including a content corresponding to the request And transmitting the first message to the participant terminals of the chat room, and storing the first message in a chat log database. The first message includes message information and a first token. The first token is calculated using the second token of the second message transmitted before the first message and the information of the first message.

Description

A method of proving the conversation contents of a social media service, the server that implemented it, the user terminal, and the application {METHOD FOR PROVIDING CONTENTS CERTIFICATION IN SOCIAL MEDIA SERVICE AND, SERVER, USER DEVICE AND APPLICATION IMPLEMENTING THE METHOD}

The present invention relates to a social media service.

There are various social media services such as KakaoTalk, Twitter, Facebook, and Instagram. Users can communicate with others through social media services and can express their thoughts. Users exchange messages with friends in chat rooms through instant messaging services such as KakaoTalk.

Until now, if users wanted to keep messages exchanged in chat rooms, they kept them without deleting the chat rooms in which messages were recorded, or captured chat rooms and kept them as images. As for how to keep the chat room, it may be difficult to find the messages that are to be archived if the chat contents continue to accumulate, the other party can leave the chat room, and if the other party leaves KakaoTalk, the other party is marked as "unknown" and the other party is specific. It may not be easy. The method of capturing a chat room and saving it as an image is capturing only one screen at a time, so there is a disadvantage of requiring screen capture of long conversation contents one by one. In addition, since such a storage method can delete messages or alter images, there may be limitations or disputes in granting legal effect as proof of conversation contents.

In addition, a server providing a social media service stores and deletes messages exchanged in chat rooms for a certain period of time. Therefore, there is a limit that the server cannot prove the contents of the conversation for messages that have passed the server storage period.

The problem to be solved by the present invention is that a server providing a social media service such as an instant messaging service generates a token that certifies the content and order of each message transmitted from the chat room, and transmits the message with the token added to the chat room participants' terminals. And, by verifying the continuity of tokens included in the messages requested for verification, it provides a method of verifying the integrity of the messages requested for verification.

In addition, the problem to be solved by the present invention is to provide a method of verifying a participant in a chat room and verifying a participant's message reception/non-reception through a hidden message.

According to an embodiment, a method for verifying conversation contents by a server providing a social media service, receiving a request input in a chat room from a first participant terminal using the social media service, including content corresponding to the request And transmitting the first message to the chat room to the participant terminals of the chat room, and storing the first message in a chat log database. The first message includes message information and a first token. The first token is calculated using the second token of the second message transmitted before the first message and the information of the first message.

The information of the first message may include at least one of a message index, a message transmission time, a message sender, a message type, and a hash value of the message content.

The request is a participation proof request, the first message is a hidden message including participation proof information of the first participant terminal, and the hidden message may be a message that is not displayed in the chat room.

The participation proof information may include information obtained by encrypting the second token or the second token.

The conversation content verification method may further include managing information on the last received message of each of the participant terminals in the chat room.

The conversation content verification method, when the second participant terminal accesses, confirming the last received message of the second participant terminal, comparing messages stored in the chatlog database with the last received message of the second participant terminal And extracting deleted message information from among untransmitted messages, and transmitting a first hidden message including the deleted message information. The deleted message information may include a token of the latest message among deleted messages.

The deleted message information may further include message information not received by the second participant terminal.

The conversation content verification method includes transmitting a second hidden message including information about transmitting the first hidden message to the second participant terminal to the participant terminals of the chat room, and the second hidden message as a chat log. It may further include storing in the database.

According to another embodiment, as a method of verifying the content of a conversation by a server providing a social media service, storing messages sent to the participant terminals of a chat room in a chatlog database, integrity of specific messages from a random participant terminal Receiving a verification request, and verifying integrity of the verification-requested messages based on tokens included in the verification-requested messages and tokens stored in the chatlog database. Each message contains message information and a token. The token is calculated using the token of the message transmitted before the message and the information of the message.

The verifying the integrity includes verifying whether tokens of the messages requested for verification are continuously calculated using message information and tokens included in the messages requested for verification, and the latest message among the messages requested for verification It may include comparing the token and the token stored in the chatlog database to verify the integrity of the messages requested for verification.

The conversation content verification method further includes the step of verifying that the specific participant participated in the chat room based on the hidden message when a hidden message including participation proof information of a specific participant exists among the messages requested for authentication. Can include.

The conversation content verification method may further include verifying that the specific participant has left the chat room if there is a message including information about leaving the chat room of a specific participant among the messages requested for authentication.

The conversation content verification method further includes the step of verifying unreceived message information of the specific participant based on the hidden message when there is a hidden message that has transmitted deleted message information to a specific participant among the messages requested for authentication. can do.

According to an embodiment, since the server verifies the integrity of the messages requested for verification by determining the continuity of the tokens added to the messages requested for verification, the user may separately save a screen or save text to prove the content of the chat room. Without the need, by selecting consecutive messages and sending them to the server, it is possible to prove the consecutive messages transmitted in the chat room.

According to the embodiment, even if the server stores only the latest messages exchanged in the chat room, it can prove the messages stored in the terminal.

1 is a block diagram of a system according to an embodiment.
2 is a flowchart illustrating a request transmission and a message transmission between a server and a chat room participant terminals according to an embodiment.
3 is a flowchart illustrating request transmission and message transmission between a server and a chat room participant terminal when a long-term non-connection according to another embodiment.
4 is a flowchart of a method for verifying conversation contents according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the embodiments of the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In addition, terms such as "... unit", "... group", and "module" described in the specification mean units that process at least one function or operation, which can be implemented by hardware or software or a combination of hardware and software. have.

The terminal includes an application, which is software stored in a computer-readable storage medium, and hardware such as a processor, memory, display, and communication module. The processor runs the application in cooperation with the hardware. The display may display a user interface screen provided by an application, receive a user input, and may receive, for example, a touch input. The communication module communicates with the messaging server through a communication network.

The terminal may be implemented in various forms, and described using a mobile terminal as an example, but may be implemented in the form of various types of computers such as a pad-type terminal such as a smart pad, a laptop computer, a wearable device, a TV terminal, and the like.

An instant messaging service using an instant messaging application as a social media service is described as an example, but it is natural that the present invention can be applied to various services in which messages including content (text, images, videos, etc.) are continuously transmitted and received.

1 is a block diagram of a system according to an embodiment.

Referring to FIG. 1, terminals 100, 110, and 120 installed with a social media application access the server 200 and use functions provided by the social media application.

An instant messaging application will be described as an example as a social media application, and the server 200 is referred to as a messaging server. The instant messaging application is a program that opens a chat room, provides an interface screen for participants to exchange messages in the chat room, and provides a service for verifying conversation contents as described in the present invention. The instant messaging application provides an interface screen in which a user selects messages for conveniently requesting verification of conversation contents, and provides an interface screen for sharing messages verified by a server.

In the present invention, "proof" includes proof of integrity that the contents and order of consecutive messages have not been altered, proof of chat room participant, and proof of message reception. The chat room participant authentication proves that the chat room participant is at the time when messages with verified integrity are exchanged. The message proof of receipt proves whether the chat room participant has received or partially received messages whose integrity has been verified. For example, a participant in a chat room proves that he did not receive a message due to a special reason (e.g., the terminal's airplane mode status due to a business trip, country specific application deactivation processing policy, loss, etc.), and through this It can be proved that it has not been notified of the change of the contract from

For explanation, it is assumed that terminal A 100 is an Aiden terminal, terminal B 110 is a Brian terminal, terminal C 120 is a Cindy terminal, and Aiden, Brian, and Cindy are participants in a chat room.

Participant terminals 100, 110, and 120 of the chat room transmit the request input in the chat room to the server 200, and the server 200 responds to the request to the participant terminals 100, 110, and 120 of the chat room. Send the corresponding message.

The server 200 receives a chat room opening request, a participant invitation request, a participant exit request, a message addition request, and a chat room opening notification message, a participant invitation notification message, a participant exit notification message to the chat room participant terminals 100, 110, 120 , Transmit a content message corresponding to the conversation. The server 200 stores a status message indicating a chat room opening, a participant invitation, a participant leaving, and the like, and a chat log of a content message input by the participants in the chat log database in order. In addition, the server 200 stores chat logs of messages transmitted between servers or terminals in order in the chat log database without being displayed in the chat room for the service to verify the contents of the conversation. Messages that are not displayed in a chat room and transmitted between servers or terminals can be called "hidden messages".

The server 200 may record chat logs for each chat room, and chat logs may be recorded as items shown in Table 1 for each message. The values used in Table 1 can be changed. Participant terminals also record messages received from the server 200 in a local storage. In Table 1, the token can be generated using the hash value of the message content.

Item Explanation index As the message number in the chat room, a sequentially increasing value is assigned,
Monotonically increasing, for example, 0001, 0002, 0003 Time Message transmission time Caller Message sender Message type 1: Reinit (chat room opening notification message)
2: Join (participant invitation notification message)
3: Leave (Notification of leaving the participant)
100: Text (input message)
101: Attachment -1: Sign (a message from the server notifying the chat room participant participation status)
-2: Missing (message in which the server transmits an unreceived message token to a terminal that has not received a message)
-3: MissingNoti (message informing other participant terminals that the server sent a Missing message to the terminal that did not receive the message) Contents Message content Content hash value Hash value of the message content = hash (message content) token The token of the Nth message is the hash value of the token of the N-1th message and the information of the Nth message (for example, at least one of index, time, sender, message type, content hash value),
For example, Nth message token = hash (N-1th message token xor Nth message information)

It is assumed that the server 200 stores chat logs for a recent certain period, for example, stores messages received during the last 3 days, and deletes messages that have passed the storage period. In this case, if messages that have passed the storage period are deleted, since it is not possible to prove unarchived messages, the server 200 may separately store tokens of the deleted messages for a certain period even if messages that have passed the storage period are deleted. Alternatively, the server 200 separately stores at least one token every certain period (eg, 1 day), and through this, even if messages that have passed the storage period are deleted, the messages requested for integrity verification can be verified with a separately stored token. have.

The server 200 manages the last received message information for each participant in the chat room. The last received message information may be the index of the last received message or the token of the last received message, but the description assumes that it is an index. When all participants have confirmed the last message, the last received message for each participant is the same. However, if Brian cannot receive the message for a specific reason, the last received message information for each participant may be different.

The server 200 periodically receives participation proof information from each of the participant terminals 100, 110, and 120. The server 200 transmits a Sign message including participation proof information to the participant terminals 100, 110, and 120. Sign message is a participation proof message proving that the participant is in the chat room. The content of the Sign message is a hidden message that includes participant authentication information, but is not displayed in the chat room. The participant identification information may be, for example, information obtained by encrypting a previous message token with the participant's secret key.

The server 200 may transmit a Missing message including a non-received message token to a message non-receiving terminal. The Missing message is a message for supplementing the token continuity of the terminal that has not received the message, and the message content includes the token of the latest unreceived message. For example, if Brian does not access the chat room for a longer period than the server storage period, the terminal B 110 does not receive the deleted messages after the server storage period. In this case, token continuity is broken in the chat log of terminal B 110 due to unreceived messages. Accordingly, since the server 200 cannot transmit the deleted message, it records long-term non-received information through the Missing message and delivers the token of the latest unreceived message. Terminal B 110 records the Missing message in the chat log.

The server 200 may transmit a MissingNoti message informing other participant terminals of the fact that the Missing message has been transmitted to the terminal B 110. The MissingNoti message may include the same content as the Missing message.

In the following, a method of transmitting and receiving a message between the server 200 and the participant terminals 100, 110, and 120 of the chat room and recording a chat log will be described.

2 is a flowchart illustrating a request transmission and a message transmission between a server and a chat room participant terminals according to an embodiment.

Referring to FIG. 2, the terminal A 100 requests the server 200 to open a chat room (S110). The request to open a chat room includes participant information.

The server 200 transmits a message including information about opening a chat room opened in response to a chat room opening request to each participant's terminal, and records the transmitted messages in the chat log database as shown in Table 2 (S120). The order of transmission and recording can be changed or performed simultaneously. Explain that the transmitted message is recorded (stored) in the chatlog database. The server 200 records a chat log of a message composed of the items in Table 1 (index: time: sender: type: content: hash value: token) as shown in Table 2. The server 200 manages the last received message information for each participant as chat room information.

Chat room information RoomInfo=LastChat{A:Nil, B:Nil, C:Nil} Chat log 0000:Time 0:Server:1(Reinit):--:ContentHash0:Token0
0001:Time1:Server:2(Join):{A}:ContentHash1=hash({A}):Token1
0002:Time2:Server:2(Join):{B}:ContentHash2=hash({B}):Token2
0003:Time3:Server:2(Join):{C}:ContentHash3=hash({C}):Token3

Each message's token is calculated using the previous message token. The method of calculating the token value may be various, and in the present invention, the “xor” operation will be described as an example. For example, Token0 can be calculated as hash(0000+time 0+Server+1+ContentHash0). Token1 can be calculated as hash(Token0 xor (0001+time 1+Server+2+ContentHash1)). Token2 can be calculated as hash(Token1 xor (0002+time 2+Server+2+ContentHash2)). Token3 can be calculated as hash(Token2 xor (0003+time 3+Server+2+ContentHash3)).

Participants enter conversation content in the chat room.

For example, when "Hello" is input in a chat room, terminal A 100 sends a request for adding a message including the input content [eg, AddMsg(100(Text), "Hello")] to the server 200 Transmit (S130).

The server 200 transmits a message (index 0004) corresponding to the message addition request to each participant's terminal, and records the transmitted message (index 0004) in the chatlog database as shown in Table 3 (S132). The message transmitted to each participant's terminal includes Token4, and Token4 can be calculated as hash(Token3 xor (0004+time 4+A+100+ContentHash4)).

Thereafter, when "nice to meet you" is input in the chat room, the terminal B 110 transmits a message addition request including the input content (eg, AddMsg(100(Text), "nice to meet you")) to the server 200. (S140).

The server 200 transmits a message (index 0005) corresponding to the message addition request to each participant's terminal, and records the transmitted message (index 0005) in the chatlog database as shown in Table 3 (S142). The message transmitted to each participant's terminal includes Token5, and Token5 can be calculated as hash(Token4 xor (0005+time 5+B+100+ContentHash5)).

When a picture file is input in the chat room, the terminal C 120 transmits a message addition request [eg, AddMsg (101(Attachment), {picture file})]) to the server 200 (S150). ).

The server 200 transmits a message (index 0006) corresponding to the message addition request to each participant's terminal, and records the transmitted message (index 0006) in the chatlog database as shown in Table 3 (S152). The message transmitted to each participant terminal includes Token6, and Token6 can be calculated as hash(Token5 xor (0006+time 6+C+101+ContentHash6)).

After the participants input the content of the conversation in the chat room, the chatlog database in Table 2 is updated as shown in Table 3. Each message's token is calculated using the previous message token. The server 200 manages the last received message information for each participant as chat room information.

RoomInfo=LastChat{A:0006, B:0006, C:0006} 0000:Time 0:Server:1(Reinit):--:ContentHash0:Token0
0001:Time1:Server:2(Join):{A}:ContentHash1=hash({A}):Token1
0002:Time2:Server:2(Join):{B}:ContentHash2=hash({B}):Token2
0003:Time3:Server:2(Join):{C}:ContentHash3=hash({C}):Token3
0004:Time4:A:100(text):Hello:ContentHash4=hash(Hello):Token4
0005:Time5:B:100(text):nice to meet you:ContentHash5=hash(nice to meet you):Token5
0006:Time 6:C:101(Attach.):{Picture File}:ContentHash6=hash({Picture File}):Token6

Each of the participant terminals 100, 110, and 120 periodically transmits a request for proof of participation to the server 200. The participation proof request is sent for the purpose of proving that you are participating in the chat room, and may be periodically sent from the application. It is assumed that a request for proof of participation is transmitted to the server 200 in the order of the terminal A 100, the terminal B 110, and the terminal C 120.

For example, the terminal A100 transmits a participation proof request (eg, addMsg(-1(sign), [Encode(Token6, secret key A)]) to the server 200 (S160). The authentication request may include participant authentication information, and may be, for example, information [Encode(Token6, private key A)] of the previous message token (Token6) encrypted with Aiden's private key.

The server 200 transmits a sign message (index 0007) corresponding to the request for proof of participation from terminal A 100 to each participant terminal, and records the transmitted sign message (index 0007) in the chatlog database as shown in Table 4. (S162). The Sign message sent to each participant's terminal includes participant proof information and Token7, and Token7 is calculated using Token6, the previous message token.

Thereafter, the other terminal also transmits the participation proof request in the same manner, and the server 200 transmits a Sign message corresponding to the participation proof request to each participant terminal.

Specifically, after the terminal B 110 receives the Sign message (index 0007), it transmits a participation proof request to the server 200, and the information obtained by encrypting the previous message token (Token7) with Brian's secret key [Encode (Token7 , Secret key B)] as participant identification information. The server 200 transmits a sign message (index 0008) corresponding to the participation proof request of the terminal B 110 to each participant terminal, and records the transmitted sign message (index 0008) in the chatlog database as shown in Table 4. .

After the terminal C 120 receives the sign message (index 0008), it transmits the participation proof request to the server 200. Information obtained by encrypting the previous message token (Token8) with Cindy's secret key [Encode (Token8, secret key C)] is transmitted as participant identification information. The server 200 transmits a sign message (index 0009) corresponding to the participation proof request of the terminal C 120 to each participant terminal, and records the transmitted sign message (index 0009) in the chatlog database as shown in Table 4. . The server 200 updates the last received message information for each participant in the chat room information.

RoomInfo=LastChat{A:0009, B:0009, C:0009} 0000:Time 0:Server:1(Reinit):--:ContentHash0:Token0
0001:Time1:Server:2(Join):{A}:ContentHash1=hash({A}):Token1
0002:Time2:Server:2(Join):{B}:ContentHash2=hash({B}):Token2
0003:Time3:Server:2(Join):{C}:ContentHash3=hash({C}):Token3
0004:Time4:A:100(text):Hello:ContentHash4=hash(Hello):Token4
0005:Time5:B:100(text):nice to meet you:ContentHash5=hash(nice to meet you):Token5
0006:Time 6:C:101(Attach.):{Picture File}:ContentHash6=hash({Picture File}):Token6
0007:Time 7:A:-1(Sign):Encode(Token6, secret key A):ContentHash7:Token7
0008:Time 8:B:-1(Sign):Encode(Token7, secret key B):ContentHash8:Token8
0009:Time 9:C:-1(Sign):Encode(Token8, secret key C):ContentHash9:Token9

Terminal C 120 transmits a request to leave the chat room (eg, addMsg(3(Leave), [Encode(Token9, secret key C)]) to the server 200 (S170). For example, it may include information [Encode (Token9, secret key C)] of the previous message token (Token9) encrypted with Cindy's secret key.

The server 200 transmits a message (index 0010) corresponding to the request to leave the chat room from the terminal C 120 to each participant terminal, and records the transmitted message (index 0010) in the chat log database as shown in Table 5 (S172). ). The message to leave the chat room can be used to verify participants.

RoomInfo=LastChat{A:0010, B:0010} 0000:Time 0:Server:1(Reinit):--:ContentHash0:Token0
0001:Time1:Server:2(Join):{A}:ContentHash1=hash({A}):Token1
0002:Time2:Server:2(Join):{B}:ContentHash2=hash({B}):Token2
0003:Time3:Server:2(Join):{C}:ContentHash3=hash({C}):Token3
0004:Time4:A:100(text):Hello:ContentHash4=hash(Hello):Token4
0005:Time5:B:100(text):nice to meet you:ContentHash5=hash(nice to meet you):Token5
0006:Time6:C:101(Attach.):{picture file}:ContentHash6=hash({picturefile}):Token6
0007:Time 7:A:-1(Sign):Encode(Token6, secret key A):ContentHash7:Token7
0008:Time 8:B:-1(Sign):Encode(Token7, secret key B):ContentHash8:Token8
0009:Time 9:C:-1(Sign):Encode(Token8, secret key C):ContentHash9:Token9
0010:Time 10:C:3(Leave):Encode(Token9, secret key C):ContentHash10:Token10

After a predetermined time elapses, the server 200 may delete messages (index 0000-0014) that have passed the server storage period as shown in Table 6 and store only the latest messages (index 0015). If Brian does not access the chat room for a longer period than the server storage period, the terminal B 110 may record a message (index 0010) as a recently received message.

RoomInfo=LastChat{A:0015, B:0010} 0015:Time 15:A:-1(Sign): Encode(Token14, Secret Key A):CH15:Token15

In this way, if Brian does not access the chat room for a longer period of time than the server storage period, terminal B 110 receives the message (index 0010) and then the deleted message (index 0011 to 0014) after the server storage period has elapsed. It cannot be done, and it can be received from the message (index 0015).

Due to the lost messages between the message (index 0010) and the message (index 0015), the continuity of the token Token10 of the message (index 0010) and the Token15 of the message (index 0015) is broken. That is, because Token15 is a value calculated from Token14.

In the following, a method for supplementing token continuity of a terminal that has not received a message will be described.

3 is a flowchart illustrating request transmission and message transmission between a server and a chat room participant terminal when a long-term non-connection according to another embodiment.

Referring to FIG. 3, terminal B 110 accesses the server 200 (S210).

The server 200 checks the last received message information (index 0010) of the terminal B 110 in the chat room information (S220).

The server 200 compares the messages stored in the chatlog database (Table 6) with the last received message of the terminal B 110 to extract unsent messages (S222). Among the untransmitted messages, messages that have already been deleted, for example, messages (index 0011) to messages (index 0014) may be included.

The server 200 transmits a Missing message including token continuity information and message not received information to the terminal B 110 (S230). The Missing message may include message information (server index and token) received by Brian, and token continuity information (not received message index and token).

The server 200 transmits the message (message 0015) stored in the chat log database (Table 6) to the terminal B 110 (S232). Alternatively, the server 200 may transmit the Missing message and the stored message (index 0015) to the terminal B 110 regardless of the order, and the message order may be modified when the terminal B 110 stores the chat log.

The server 200 transmits the MissingNoti message to the participant terminals so that the other participant terminals can know that the Missing message has been transmitted to the terminal B 110, and records the MissingNoti message in the chatlog database (S240). The content of the MissingNoti message includes the content of the Missing message, allowing other participants to know the content of the Missing message.

The chatlog database of the server 200 is shown in Table 7.

RoomInfo=LastChat{A:0016, B:0016} 0015:Time 15:A:-1(Sign): Encode(Token14, Secret Key A):CH15:Token15
0016:Time 16:Server:-3(MissingNoti): {B, 10:Token10, 14:Token14}:CH16:Token16

The chat log database of terminal A 100 is shown in Table 8.

0000:Time 0:Server:1(Reinit):--:CH0:Token0
0001:Time 1: Server:2(Join):{A}:CH1:Token1
0002:Time2:Server:2(Join):{B}:CH2:Token2
0003:Time3:Server:2(Join):{C}:CH3:Token3
0004:Time4:A:100(text):Hello:CH4:Token4
0005:Time5:B:100(text):nice to see you:CH5:Token5
0006:Time 6:C:101(Attach.):{Picture File}:CH6:Token6
0007:Time 7:A:-1(Sign):Encode(Token6, secret key A):CH7:Token7
0008:Time 8:B:-1(Sign):Encode(Token7, secret key B):CH8:Token8
0009:Time 9:C:-1(Sign):Encode(Token8, secret key C):CH9:Token9
0010:Time 10:C:3(Leave):Encode(Token9, Secret key C):CH10:Token10
0011:Time 11:A:100(text):This is an interesting photo:CH11:Token11
0012:Time 12:A:100(text):The weather is nice today:CH12:Token12
0013:Time 13:B:100(text):Yes:CH13:Token13
0014:Time 14:B:100(text): But it rains in the afternoon: CH14:Token14
0015:Time 15:A:-1(Sign):Encode(Token14, Secret Key A):CH15:Token15
0016:Time 16:Server:-3(MissingNoti):{B, 10:Token10, 14:Token14}:CH16:Token16

The chat log database of terminal B 110 is shown in Table 9.

0000:Time 0:Server:1(Reinit):--:CH0:Token0
0001:Time 1: Server:2(Join):{A}:CH1:Token1
0002:Time2:Server:2(Join):{B}:CH2:Token2
0003:Time3:Server:2(Join):{C}:CH3:Token3
0004:Time4:A:100(text):Hello:CH4:Token4
0005:Time5:B:100(text):nice to see you:CH5:Token5
0006:Time 6:C:101(Attach.):{Picture File}:CH6:Token6
0007:Time 7:A:-1(Sign):Encode(Token6, secret key A):CH7:Token7
0008:Time 8:B:-1(Sign):Encode(Token7, secret key B):CH8:Token8
0009:Time 9:C:-1(Sign):Encode(Token8, secret key C):CH9:Token9
0010:Time 10:C:3(Leave):Encode(Token9, Secret key C):CH10:Token10
0011:Time 11:Server:-2(Missing):{B, 10:Token10, 14:Token14}:CH11:Nil
0015:Time 15:A:-1(Sign):Encode(Token14, Secret Key A):CH15:Token15
0016:Time 16:Server:-3(MissingNoti):{B, 10:Token10, 14:Token14}:CH16:Token16

4 is a flowchart of a method for verifying conversation contents according to an embodiment.

Referring to FIG. 4, terminal A 100 selects messages stored therein, and requests integrity verification to server 200 (S310). The messages requested for authentication are, for example, from the message (index 0006) in Table 8 to the message (index 0016). The integrity verification request may be transmitted not only from the chat room participant terminal, but also from various devices capable of transmitting the messages requested for verification.

The server 200 verifies the token continuity of tokens included in the messages for which authentication is requested (S320). In this case, the server 200 may verify the token continuity step by step while confirming the integrity of the token whether the token of each transmitted message is generated from the content of the message. When the token continuity is denied, since there is a forgery of a message, the server 200 transmits a failure to verify the integrity of the messages requested for verification.

When the token continuity is confirmed, the server 200 compares the token 16 of the latest message of the messages requested for verification with the token 16 of the corresponding message stored in the chatlog database (S330).

The server 200 verifies the integrity of the messages requested for verification based on the comparison result of the latest message token received from the terminal and the stored message token (S340). The order of steps S320 and S330 may be changed.

The server 200 transmits the results of verifying the integrity of the messages requested for authentication to the terminal A 100 (S350).

That is, the server 200 checks whether Token7 is calculated using Token6 of the messages requested for authentication and information (0007:time7:A:-1(Sign):CH7) of the message (index 0007), and then The token value (Token16) of the last message (index 0016) requested for verification is derived while checking whether Token8 is calculated using the information in the message (index 0008). Even if the content of the message is forged in the terminal, the token value is not changed, so the server 200 checks whether a token of the message is generated from the message content. If the continuity of the tokens is broken, since there is a forgery message, the server 200 denies the integrity of the messages requested for verification. The server 200 may compare the token 16 of the stored message (index 0016) with the token value Token16 whose token continuity is confirmed to verify the integrity of the messages requested for verification.

While verifying the token continuity, the server 200 discovers the MissingNoti message, and through this, it is possible to confirm that Brian received the message (index 0010) and not received the message (index 0011) to the message (index 0014). While verifying the token continuity, the server 200 may confirm that Cindy received the message (index 0009) and left the chat room.

Terminal B 110 selects messages stored therein and requests the server 200 to verify integrity in the same manner. Referring to Table 9, the server 200 may check the token 14 of the lost message through the Missing message recorded in the terminal B 110, and verify continuity of the next message based on this. In addition, the server 200 may check Brian's unreceived messages through the Missing message.

In FIG. 4, since the latest message (index 0016) among the messages requested for verification is stored in the server 200, the server 200 is a token 16 and a chat log of the latest message of the messages requested for verification in step S330. The token (Token16) of the message stored in the database can be compared.

According to an embodiment, when the server 200 stores only tokens of messages for a storage period (for example, 3 days), the messages requested for verification should include at least one message that has not passed the message storage period of the server. And, if not, it may receive a reselection request from the server. Alternatively, messages that have not passed the server's message retention period can be automatically selected to be included.

According to another embodiment, even if the server 200 deletes messages that have passed the storage period, at least some tokens of the deletion messages may be separately stored. For example, the server 200 may store tokens of deletion messages and extract and compare a token corresponding to at least one message among messages requested for verification from among the stored tokens.

Alternatively, the server 200 may separately store at least one token (eg, a token of the last message transmitted on the same day) every predetermined period (eg, 1 day). In this case, the messages requested for authentication may be automatically or manually selected to include the last message of the period. For example, even if the server 200 deletes the messages transmitted to the chat room 10 days ago, the message token last transmitted on January 2nd, 10 days before, is stored as information for verifying the contents of the conversation on January 2nd. Thereafter, when the server 200 receives the message transmitted on January 1 and the last message transmitted on January 2 as a proof request message, the January 2 token stored for proof of conversation contents on January 2 The step S330 of FIG. 4 may be processed by using.

Until now, the terminal has been described as receiving and storing messages from the server, but when the terminal receives a message from the server, it can verify continuity with the previously received message. That is, the terminal determines whether the value obtained by hashing the TokenX of the N-1th received message and the information of the Nth received message is the same as the TokenY of the Nth received message, and if not, determines that the message is not a continuous message (the message is May be deleted or not received). The terminal may report a synchronization failure with the server to the server. The terminal or server may inform the user that it is no longer possible to prove the contents of the chat room. Alternatively, the server may guarantee token continuity by transmitting a Missing message to the terminal so that the content of the conversation can be verified continuously.

According to the embodiment, since the server verifies the integrity of the messages requested for verification by determining the continuity of the tokens added to the messages for which verification is requested, the user needs to separately save the screen save text to prove the content of the conversation in the chat room. Without, by selecting consecutive messages and sending them to the server, it is possible to prove the consecutive messages transmitted in the chat room.

According to the embodiment, even if the server stores only the latest messages exchanged in the chat room, it can prove the messages stored in the terminal.

The embodiments of the present invention described above are not implemented only through an apparatus and a method, but may be implemented through a program that realizes a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (13)

As a method for a server providing a social media service to prove the contents of a conversation,
Receiving, from a first participant terminal using the social media service, a participation proof request proving that the first participant terminal is participating in a chat room,
Transmitting a first message for proof of participation of the first participant terminal to participant terminals of the chat room, and
Including the step of storing the first message in a chat log database,
The first message includes message information and a first token,
The first token is calculated using the second token of the second message transmitted before the first message and the information of the first message,
The third message transmitted after the first message includes the first token and a third token calculated using information of the third message,
The integrity of the second message, the first message, and the third message is verified according to whether the first token is calculated from the second token and the third token is calculated from the first token. Proof method. In claim 1,
The information of the first message is
Conversation content verification method including at least one of a message index, message transmission time, message sender, message type, and hash value of the message content. In claim 1,
The first message is a hidden message,
The hidden message is a message that is not displayed in the chat room. In paragraph 3,
The first message includes participation proof information of the first participant terminal,
The participation proof information includes information obtained by encrypting the second token or the second token. In claim 1,
Managing the last received message information of each of the participant terminals in the chat room
Conversation content proof method further comprising. In clause 5,
When the second participant terminal accesses, confirming the last received message of the second participant terminal,
Comparing the messages stored in the chatlog database with the last received message of the second participant terminal, and extracting deleted message information from among unsent messages, and
Further comprising the step of transmitting a first hidden message including the deleted message information,
The deleted message information includes a token of the latest message among deleted messages. In paragraph 6,
The deleted message information is
Conversation content verification method further comprising message information not received by the second participant terminal. In paragraph 6,
Transmitting a second hidden message including information on transmitting the first hidden message to the second participant terminal to the participant terminals of the chat room, and
Storing the second hidden message in a chatlog database
Containing, conversation content proof method. As a method for a server providing a social media service to prove the contents of a conversation,
Storing messages sent to the participants terminals of the chat room in the chat log database,
Receiving an integrity certificate request for specific messages from a random participant terminal, and
And verifying the integrity of the authentication-requested messages based on tokens included in the authentication-requested messages and tokens stored in the chatlog database,
Each message contains message information and a token,
The token is calculated using the token of the message transmitted before the message in the chat room and information of the message,
The step of verifying the integrity is
Verifying that tokens of the authentication-requested messages are continuously calculated using message information and tokens included in the authentication-requested messages, and
Comparing the token of the latest message among the messages requested for verification with a token stored in the chatlog database to verify the integrity of the messages requested for verification
Conversation content proof method comprising a. delete In claim 9,
Proving that the specific participant participated in the chat room based on the hidden message, if there is a hidden message including participation proof information of a specific participant among the messages requested for proof
Conversation content proof method further comprising. In claim 9,
Proving that the specific participant has left the chat room if there is a message including information about leaving the chat room of a specific participant among the messages requested for verification
Conversation content proof method further comprising. In claim 9,
Proving unreceived message information of the specific participant based on the hidden message when there is a hidden message that has transmitted deleted message information to a specific participant among the messages requested for authentication
Conversation content proof method further comprising.

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