WO2021115290A1

WO2021115290A1 - Off-chain random number application method and device for blockchain game, and storage medium

Info

Publication number: WO2021115290A1
Application number: PCT/CN2020/134727
Authority: WO
Inventors: 俞铠俊; 王志文; 吴思进
Original assignee: 杭州复杂美科技有限公司
Priority date: 2019-12-13
Filing date: 2020-12-09
Publication date: 2021-06-17
Also published as: CN111185011A; CN111185011B

Abstract

An off-chain random number application method and device for a blockchain game, and a storage medium. The method comprises: generating a first random number and first encrypted information, and broadcasting the first encrypted information to second user ends; receiving and storing second encrypted information respectively broadcasted by the second user ends; generating n-2 third random numbers and fourth random numbers, and sending same to n-1 second user ends respectively; receiving and storing fifth random numbers or sixth random numbers respectively sent by the second user ends; when second random numbers broadcasted by a first second user end are not received promptly, broadcasting the fifth random numbers or the sixth random numbers generated by the user end; receiving the fifth random numbers or the sixth random numbers generated by the user end and broadcasted by other second user ends; generating second random numbers generated by the user end according to n-2 fifth random numbers and sixth random numbers generated by the user end; and generating an off-chain random number.

Description

Off-chain random number application method, equipment and storage medium for blockchain games

Technical field

This application relates to the technical field of blockchain games, in particular to an off-chain random number application method, device and storage medium for blockchain games.

Background technique

Blockchain game mechanisms that are not on the chain during the game's opening phase and settlement phase, and the middle game process stage is not on the chain, or the transaction mechanism of off-chain transactions based on channels registered on the blockchain (refer to CN201911073994.9) In the blockchain game mechanism, when a random number is needed during the game, it is necessary to ensure that the random number is not predicted or manipulated by the user to avoid cheating.

One way to solve the above random number problem is to use random numbers generated on the blockchain (for example, the random number generation method provided by CN109558112A). However, the problem with this method is that the generation of random numbers depends on the mining mechanism of the blockchain, and the mining and block generation speed of the blockchain is limited. Therefore, the number of random numbers that can be provided is limited. When you need to use more random numbers in the game, the number of random numbers on the chain cannot meet the needs of the game.

Another way to solve the above random number problem is to generate off-chain random numbers jointly by all users participating in the game. For example, if user A/B/C plays a game, the result of the game needs to be generated based on the random number r. The A/B/C user terminal generates random numbers a/b/c and broadcasts hash(a)/hash( b)/hash(c), so that when the game result needs to be generated, the verifiable a/b/c are broadcasted separately, and the random number r=f(a,b,c) is generated, so as to ensure that the random number r will not be used by the user Predict or manipulate. However, a problem with this method is that when the client of A/B broadcasts a/b and the client of C has not broadcast c, the client of C can already generate a random number r and learn the game result. When the user When C learns that the game result is unfavorable, he may choose to go offline or forcibly close the game client without broadcasting c. As a result, the A/B client cannot generate the game result and can only save the evidence and report the user C, which greatly affects the game user Experience.

Summary of the invention

In view of the above-mentioned shortcomings or deficiencies in the prior art, it is desirable to provide a blockchain game chain that guarantees that when a user maliciously goes offline in a multiplayer game, off-chain random numbers and game results can be generated to enhance the game user experience. Under the random number application method, equipment and storage medium, and further hope to improve the random number mechanism under the chain.

In the first aspect, the present invention provides an off-chain random number application method for a blockchain game. The number of participants in the game is n, and n is not less than 3. The method is suitable for the user side, and the method includes:

Generate a first random number, and encrypt the first encrypted information generated by encrypting the first random number, and broadcast the first encrypted information to each second user terminal participating in the game;

Receiving and storing the second encrypted information respectively broadcast by each second user terminal; wherein the second encrypted information is generated by encrypting the corresponding second random number by the second user terminal;

Generate n-2 third random numbers, and generate a fourth random number based on the first random number and n-2 third random numbers, and send n-2 third random numbers and fourth random numbers to n- One second client, so that each second client holds a third random number or a fourth random number;

Receive and store the fifth random number or the sixth random number respectively sent by each second user end; wherein, the fifth random number is generated by the second user end, and the sixth random number is generated by the second user end according to the second random number and n -2 fifth random number generation;

Monitor whether the second random number broadcast by each second user terminal is received during the period of generating the random number under the chain:

If the second random number broadcast by the first and second client is not received, broadcast the fifth random number or the sixth random number generated by the first and second client; and,

Receiving the fifth random number or the sixth random number generated by the first and second user terminals broadcast by each second user terminal except the first and second user terminals;

Generating a second random number generated by the first and second user end according to the n-2 fifth random numbers and the sixth random number generated by the first and second user end;

Generate an off-chain random number according to the first random number, the received n-2 second random numbers, and the generated 1 second random number.

In a second aspect, the present invention also provides a device, including one or more processors and a memory, where the memory contains instructions executable by the one or more processors to make the one or more processors execute each of the instructions according to the present invention. The embodiment provides an off-chain random number application method for blockchain games.

In a third aspect, the present invention also provides a storage medium storing a computer program that enables the computer to execute the off-chain random number application method of the blockchain game according to the embodiments of the present invention.

The off-chain random number application method, device, and storage medium for blockchain games provided by many embodiments of the present invention divide the random number generated by each user into multiple copies and send them to participants in a multiplayer game. Other users of this game make that when any user does not announce the random number generated by itself over time, other users can restore the unannounced random number after the timeout according to the random number fragments stored in their own, so as to generate off-chain random numbers to ensure The generation of game results improves the game user experience;

The off-chain random number application method, device and storage medium for blockchain games provided by some embodiments of the present invention further ensure that random number fragments are generated and sent after all the game links related to off-chain random numbers in the game are over. Other users of this game colluded to get the random number under the chain in advance, and they cannot cheat or affect the result of the game;

The off-chain random number application method, device, and storage medium of blockchain games provided by some embodiments of the present invention further encrypt and broadcast the fragment encrypted information after receiving the random number fragment, so that each user terminal can Verify that the received random number fragments are correct, and further improve the off-chain random number mechanism;

The off-chain random number application method, device, and storage medium of blockchain games provided by some embodiments of the present invention further complete the off-chain random number storage certificate by signing random number encrypted information, fragmented encrypted information and random numbers. And proof mechanism.

Description of the drawings

By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present application will become more apparent:

FIG. 1 is a flowchart of an off-chain random number application method for blockchain games according to an embodiment of the present invention.

Fig. 2 is a flowchart of step S17 in a preferred embodiment of the method shown in Fig. 1.

FIG. 3 is a schematic structural diagram of a device provided by an embodiment of the present invention.

Detailed ways

The application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the related invention, but not to limit the invention. In addition, it should be noted that, for ease of description, only the parts related to the invention are shown in the drawings.

It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other if there is no conflict. Hereinafter, the application will be described in detail with reference to the drawings and in conjunction with the embodiments.

As shown in Figure 1, in this embodiment, the present invention provides an off-chain random number application method for a blockchain game. The number of participants in the game is n, and n is not less than 3. This method is suitable for the user side. Methods include:

S11: Generate a first random number, and encrypt the first encrypted information generated by encrypting the first random number, and broadcast the first encrypted information to each second user terminal participating in the game;

S13: Receive and store the second encrypted information respectively broadcasted by each second client; where the second encrypted information is generated by encrypting the corresponding second random number by the second client;

S15: Generate n-2 third random numbers, generate a fourth random number according to the first random number and n-2 third random numbers, and send n-2 third random numbers and fourth random numbers to n-1 second client terminals, so that each second client terminal holds a third random number or a fourth random number respectively;

S17: Receive and store the fifth random number or the sixth random number respectively sent by each second user end; wherein, the fifth random number is generated by the second user end, and the sixth random number is generated by the second user end according to the second random number And n-2 fifth random number generation;

S191: Monitor whether the second random number broadcast by each second user terminal is received during the period of time when the off-chain random number is generated:

S193: If the second random number broadcast by the first and second client is not received, broadcast the fifth random number or the sixth random number generated by the first and second client; and,

S194: Receive the fifth random number or the sixth random number generated by the first and second user terminals broadcast by each second user terminal except the first and second user terminals;

S195: Generate a second random number generated by the first and second user end according to the n-2 fifth random numbers and the sixth random number generated by the first and second user end;

S196: Generate an off-chain random number according to the first random number, the received n-2 second random numbers, and the generated 1 second random number.

In the following, taking n=3, user ABC plays a three-person game, and the game result needs to be generated based on multiple off-chain random numbers as an example, the above method is exemplified.

Take the generation of random numbers under the chain r ₁ as an example (generating random numbers under other chains is the _{same as generating r 1} and will not repeat them one by one):

In step S11, the UE of user A generates a first random number r _a, and the base point G r _a multiplying elliptic curve algorithm to encrypt r _a, generating a first encrypted information r _a G, and B to the user user C's terminal broadcast r _a G;

In the same way, the user terminal of user B generates the second random number r _b and the second encrypted information r _b _{G, and broadcasts r b} G to the user terminals of users A and C;

The user terminal of user C generates a second random number r _c and second encrypted information r _c _{G, and broadcasts r c} G to the user terminals of users A and B;

In step S13, the user terminal of user A receives and stores r _b G and r _c G respectively;

In the same way, the user terminal of user B receives and stores r _a G and r _c G respectively;

The user terminal of user C receives and stores r _a G and r _b G respectively;

In step S15, the UE of user A generates a random number r _a1 third, and fourth random number r _a2 = r _a -r _a1, r _a1 transmits to the user terminal of user B, is sent to the r _a2 The user terminal of user C (also can send _ra2 to the user terminal of user B, and send _ra1 to the user terminal of user C, that is, it can be randomly allocated, the same below);

Similarly, the user end of user B generates a fifth random number r _b1 and a sixth random number r _b2 =r _b -r _b1 , and sends r _b1 to the user end of user A, and sends r _b2 to user C. user terminal;

The user end of user C generates a fifth random number r _c1 and a sixth random number r _c2 =r _c -r _c1 , and sends r _c1 to the user end of user A, and sends r _c2 to the user end of user B;

In step S17, the user terminal of user A receives and stores r _b1 and r _{c1 respectively} ;

In the same way, the user terminal of user B receives and stores r _a1 and r _{c2 respectively} ;

The user terminal of user C receives and stores _ra2 and r _{b2 respectively} ;

In step S191, the user terminal of user A _{monitors whether it receives the second random numbers r b} and r _c broadcasted by the user terminals of users B and C during the period _{when the off-chain random number r 1} is generated:

When the user terminals of users B and C broadcast r _b and r _c normally, the user terminal of user A receives r _b and r _c , and verifies r _b and r respectively according to the stored r _b G and r _{c G stored in step S13} _c is correct:

_{If yes, generate an off-chain random number r 1} =f(r _a ,r _b ,r _c ) according to the pre-configured random number generation function f();

When the user terminals of user B and C are offline at the same time, or the user terminal of user A is offline, the user terminal of user A does not receive r _b and r _c , by checking whether the network connection of the current user terminal is normal, sending the request again Processing methods commonly used in this field;

When the client of user B goes offline maliciously or accidentally offline, and the client of user C broadcasts r _c normally, and the client of user A receives r _c but not r _b , then step S193 is executed: the client of user A Broadcast to the user terminal of user C the fifth random number r _b1 generated by the user terminal of user B;

_{Similarly, the user terminal of user C broadcasts the sixth random number r b2} generated by the user terminal of user B to the user terminal of user A;

In step S194, the user terminal of user A receives r _b2 broadcast by the user terminal of user C;

Similarly, the user terminal of user C receives r _b1 broadcast by the user terminal of user A;

In step S195, the user terminal of user A generates r _b _{according to r b1} and r _b2 : r _b =r _b1 +r _b2 ;

Similarly, the user terminal of user C generates r _b _{according to r b1} and r _b2 ;

In step S196, the user terminal of user A, after verifying r _b and r _c _{according to r b} G and r _c G, generates an off-chain random number r ₁ =f(r _a ,r _b ,r _{c according to f()} );

After Similarly, the client user C respectively and verification r _a r _a r _b The G and r _b G, according to f () to generate the random number strand _{_{r 1 = f (r a,}} r b, r c).

In the above example, the method shown in FIG. 1 is exemplarily explained by taking the way that the number of players is three and the encrypted random number is configured to multiply the random number by the base point G of the elliptic curve algorithm. In more embodiments , The method shown in Figure 1 is also applicable to multiplayer games with different numbers of people such as four-player games and five-player games, as long as the number of players is not less than 3; the method of encrypting random numbers can also be configured as other commonly used in the field The encryption algorithm of the plaintext cannot be reversed based on the ciphertext, and the same technical effect can be achieved.

In the above embodiment, in a multiplayer game, each client splits the random number generated by itself into multiple copies and sends them to other client terminals participating in the game, so that the random number generated by itself is not published on any client side over time. At the time, other users can restore the random number that has not been announced after the timeout according to their stored random number fragments, thereby generating an off-chain random number, ensuring the generation of game results, and improving the game user experience.

In a preferred embodiment, step S15 includes:

After all the game links related to random numbers off the chain in this game are over, n-2 third random numbers are generated, and the fourth random number is generated according to the first random number and n-2 third random numbers, and n -2 third random numbers and fourth random numbers are respectively sent to n-1 second client terminals, so that each second client terminal holds a third random number or a fourth random number respectively.

Specifically, although the method shown in Figure 1 guarantees the generation of off-chain random numbers, it causes new security risks. For example, in the above-described three game user ABC conducted, if the user of the user terminal A before _a game session associated with r r UE will not end _a1 sent to user B, user C sent to r _A2 On the user side, there is a security risk that users B and C can collude to generate r ₁ in advance, thereby cheating in the game. Worse, this mechanism may cause users to have a psychological game of "if I don't collude to cheat, I will suffer if others collude and cheat", thereby inducing some users to try to collude and cheat.

In view of the aforementioned security risks, step S15 is configured to be executed after all game links related to off-chain random numbers in the game are over, so that even if the colluding users generate r ₁ in advance, they cannot cheat and gain profit. The result of the game can only be known in advance.

The above embodiment further generates and sends random number fragments after all the game links related to the off-chain random number of the game in this game are over, which ensures that other users of the game of this game collude to learn the off-chain random number in advance and cannot cheat or affect the game result. .

As shown in Figure 2, in a preferred embodiment, step S17 includes:

S171: Receive the fifth random number or the sixth random number sent by the second user end;

S173: Encrypt the fifth random number or the sixth random number to generate third encrypted information, and broadcast the third encrypted information to each second user end except the second second user end;

S175: Receive the fourth encrypted information respectively broadcasted by each second user end except the second second user end; wherein the fourth encrypted information is encrypted by the second user end and the fifth random number sent by the second second user end or The sixth random number is generated;

S177: Verify the third encrypted information and each fourth encrypted information according to the second encrypted information broadcast by the second second client:

If the verification is successful, step S179 is executed: the fifth random number or the sixth random number sent by the second second user terminal is stored.

Specifically, also take user ABC playing a three-person game as an example:

In step S171, the user terminal of user A receives r _b1 and r _c1 (the same is true for the user terminals of users B and C, which will not be listed one by one, the same below);

In step S173, the UE of user A to r _b1 encrypted to generate r _b1 G, the r _b1 G broadcast to the UE user C; of r _c1 encrypted to generate r _c1 G, the r _c1 G broadcast to User B's client;

In step S175, the user terminal of user A respectively receives r _b2 _{G broadcast by the user terminal of user C and r c2} G broadcast by the user terminal of user B;

In step S177, the user terminal of user A respectively checks whether r _b1 G+r _b2 G is the same as _{r b} G received and stored in step S13 _{, and whether r c1} G+r _c2 G is the same as _{r c G:}

If the verification is successful, step S179 is executed to store r _b1 and r _c1 ;

If the verification fails, you can re-request the r _b1 and/or r _c1 that failed the verification from the corresponding client, or send an error message to the corresponding client, and you can also save the proof for proof.

In the above embodiment, after receiving the random number fragments, each user terminal encrypts the generated fragment encrypted information and broadcasts it, so that each user terminal can verify whether the received random number fragment is correct, and further improve the off-chain random number mechanism.

In a preferred embodiment, the first encrypted information, each third random number, and the fourth random number broadcast in the foregoing embodiment are signed by the current user, and the received second encrypted information, fifth random number or sixth random number The number is signed by the corresponding user.

Specifically, in the method provided in the foregoing embodiment, there is still the possibility that some users maliciously broadcast wrong data, and each user can record the received signed data for proof by signing.

The foregoing embodiment further improves the off-chain random number storage and proof mechanism by signing the random number encrypted information, fragmented encrypted information, and random number.

As shown in FIG. 3, as another aspect, the present application also provides a device 300, including one or more central processing units (CPU) 301, which can be based on a program stored in a read-only memory (ROM) 302 or The program loaded from the storage section 308 into the random access memory (RAM) 303 executes various appropriate actions and processing. In the RAM 303, various programs and data required for the operation of the device 300 are also stored. The CPU301, the ROM302, and the RAM303 are connected to each other through a bus 304. An input/output (I/O) interface 305 is also connected to the bus 304.

The following components are connected to the I/O interface 305: an input part 306 including a keyboard, a mouse, etc.; an output part 307 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and speakers, etc.; a storage part 308 including a hard disk, etc. ; And a communication section 309 including a network interface card such as a LAN card, a modem, and the like. The communication section 309 performs communication processing via a network such as the Internet. The driver 310 is also connected to the I/O interface 305 as needed. A removable medium 311, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 310 as needed, so that the computer program read from it is installed into the storage portion 308 as needed.

In particular, according to the embodiments of the present disclosure, the method described in any of the above embodiments may be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program tangibly embodied on a machine-readable medium, and the computer program includes program code for executing any of the foregoing methods. In such an embodiment, the computer program may be downloaded and installed from the network through the communication part 309, and/or installed from the removable medium 311.

As yet another aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium may be the computer-readable storage medium included in the device of the above-mentioned embodiment; The computer-readable storage medium in the device. The computer-readable storage medium stores one or more programs, and the programs are used by one or more processors to execute the methods described in this application.

The flowcharts and block diagrams in the drawings illustrate the possible implementation architecture, functions, and operations of the system, method, and computer program product according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, program segment, or part of code, and the module, program segment, or part of code contains one or more for realizing the specified logical function Executable instructions. It should also be noted that, in some alternative implementations, the functions marked in the block may also occur in a different order from the order marked in the drawings. For example, two blocks shown one after the other may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and/or flowchart, and the combination of the blocks in the block diagram and/or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or operations Or it can be realized by a combination of dedicated hardware and computer instructions.

The units or modules involved in the embodiments described in the present application can be implemented in software or hardware. The described units or modules may also be arranged in the processor. For example, each unit may be a software program arranged in a computer or a mobile smart device, or may be a separately configured hardware device. Among them, the names of these units or modules do not constitute a limitation on the units or modules themselves under certain circumstances.

The above description is only a preferred embodiment of the present application and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover the above technical features or technical solutions without departing from the concept of the application. Other technical solutions formed by arbitrarily combining the equivalent features. For example, the above-mentioned features and the technical features disclosed in this application (but not limited to) with similar functions are mutually replaced to form a technical solution.

Claims

An off-chain random number application method for a blockchain game is characterized in that the number of participants in the game is n, and n is not less than 3. The method is suitable for the user side, and the method includes:

Generating a first random number, and encrypting the first encrypted information generated by encrypting the first random number, and broadcasting the first encrypted information to each second user terminal participating in the game;

Receiving and storing the second encrypted information respectively broadcasted by each of the second client terminals; wherein the second encrypted information is generated by encrypting the corresponding second random number by the second client terminal;

Generate n-2 third random numbers, and generate a fourth random number according to the first random number and the n-2 third random numbers, and combine the n-2 third random numbers with the first random number Four random numbers are respectively sent to n-1 said second client terminals, so that each of said second client terminals holds a third random number or a fourth random number respectively;

Receive and store the fifth random number or the sixth random number sent by each of the second client terminals; wherein the fifth random number is generated by the second client terminal, and the sixth random number is generated by the first client terminal. 2. The user terminal generates according to the second random number and n-2 fifth random numbers;

Monitoring whether the second random number broadcast by each of the second user terminals is received during the period of generating the random number under the chain:

If the second random number broadcast by the first and second client is not received, broadcast the fifth random number or the sixth random number generated by the first and second client; and,

Receiving a fifth random number or a sixth random number generated by the first and second user terminals broadcast by each of the second user terminals except the first and second user terminals;

Generating the second random number generated by the first and second user end according to the n-2 fifth random numbers and the sixth random number generated by the first and second user end;

An off-chain random number is generated according to the first random number, the received n-2 second random numbers, and the generated 1 second random number.
The method according to claim 1, wherein the generating n-2 third random numbers, and generating a fourth random number according to the first random number and the n-2 third random numbers, The n-2 third random numbers and the fourth random numbers are respectively sent to n-1 second client terminals, so that each of the second client terminals holds a third random number or a third random number. Four random numbers include:

After all the game links related to the off-chain random number in this game are over, n-2 third random numbers are generated, and the first random number is generated according to the first random number and the n-2 third random number. Four random numbers, sending n-2 of the third random number and the fourth random number to n-1 of the second client terminals respectively, so that each of the second client terminals holds a third Random number or fourth random number.
The method according to claim 1 or 2, wherein the receiving and storing the fifth random number or the sixth random number respectively sent by each of the second user terminals comprises:

Receiving the fifth random number or the sixth random number sent by the second second user terminal;

Encrypting the fifth random number or the sixth random number to generate third encrypted information, and broadcasting the third encrypted information to each of the second client terminals except the second second client terminal;

Receiving fourth encrypted information broadcasted by each of the second client terminals except the second second client terminal; wherein the fourth encrypted information is sent by the second client terminal encrypted by the second client terminal Generated by the fifth random number or the sixth random number;

Verify the third encrypted information and each of the fourth encrypted information according to the second encrypted information broadcast by the second second client: if the verification is successful, the fifth sent by the second second client is stored Random number or sixth random number.
The method according to claim 3, wherein each user terminal encrypts the random number in a manner configured to multiply the random number by the base point G of the elliptic curve algorithm.
The method according to claim 1 or 2, wherein the broadcasted first encrypted information, each third random number and the fourth random number are signed by the current user, and the received second encrypted information and fifth random number Or the sixth random number is signed by the corresponding user.
A device, characterized in that the device includes:

One or more processors;

Memory, used to store one or more programs,

When the one or more programs are executed by the one or more processors, the one or more processors are caused to execute the method according to any one of claims 1-5.
A storage medium storing a computer program, characterized in that, when the program is executed by a processor, the method according to any one of claims 1-5 is implemented.