Computer implemented method for fraud-resistant disclosure of secret information

BACKGROUND OF THE INVENTION

Conventional processes of disclosing secret information generally involve a trusted party that is in possession of the secret information and that transmits the secret information to a recipient at a disclosure date. Due to the secret nature of the information, the recipient thereby has to rely on the trustworthiness of the trusted party. In many cases, however, this represents an undesirable situation, in particular if the disclosed secret information triggers further consequences. As an example, such secret information may contain predetermined winning numbers of a lottery. The recipient of the winning numbers, e.g. a participant of the lottery, has a strong interest in knowing whether or not the disclosed winning numbers coincide with the originally predetermined winning numbers. In other words, the participant of the lottery wants to be ensured that the organizer of the lottery does not disclose fraudulently altered secret information in order to influence the outcome of the lottery in his favour.

Therefore, a method for fraud-resistant disclosure of predetermined secret information is desirable that enables the recipient to verify the correctness of the disclosed secret information.

SUMMARY

According to one of many embodiments, there is provided a method performed by a first computing device for fraud-resistant transmission of secret information, the method comprising the steps of: receiving a request for secret information, wherein the request indicates a first point in time at or after which the secret information is to be transmitted to a second computing device; transmitting, at a second point in time prior to the first point in time, encrypted data to the second computing device, the encrypted data comprising the secret information; and transmitting, at or after the first point in time, an encryption key to the second computing device, the encryption key to decrypt the encrypted data.

The described method enables the second computing device to be in possession of the data comprising the secret information before a disclosure date of the secret information, i.e. before the secret information is effectively transmitted to the second computing device by transmitting the encryption key. In other words: The second computing device is in possession of the secret information whilst still being ignorant of the content of the secret information. Thereby, the second computing device is protected from receiving fraudulently altered secret information at the predetermined date of disclosure. The described method therefore improves the reliability of transmitted secret information.

According to an embodiment, the computer implemented method further comprises: determining, in particular generating the secret information subsequent to receiving the request for secret information.

Therefore, no party other than the first computing device is aware of the content of the secret information and only the first computing device is able to disclose the secret information at the predetermined date of disclosure, i.e. the first point in time. Hence, the level of confidentiality of the secret information is increased.

According to an embodiment, the request further indicates an information type of the secret information to be transmitted; and wherein the determined secret information is of said information type.

This enables the requestor of the secret information to adjust the nature of the requested secret information based on the application the secret information is needed for. In other words: The method is able to adapt to specific requirements set out by the requestor.

According to an embodiment, the transmitted encrypted data and/or the transmitted encryption key comprises an identifier associated with the secret information and/or the received request. In that manner, the second computing device is enabled to unambiguously assign the received secret information to the respective request. Hence, received secret information of a certain type is prevented from being erroneously assigned to a different request.

According to an embodiment, the computer implemented method further comprises: receiving, from the second computing device, a request for the encryption key at a third point in time; determining whether the third point in time is prior to the first point in time; and transmitting the encryption key upon request, if the third point in time is not prior to the first point in time.

Thereby, in circumstances in which the exact disclosure date is unknown at the time the request for secret information is received by the first computing device, the requestor may set a point in time until which the information shall be kept secret at least, i.e. may set a minimum time period during which the secret information shall not be disclosed. With the expiry of said minimum time period, the second computing device is itself enabled to determine the date of disclosure by requesting the decryption key. In that manner, the ability of the described method to adapt to specific requestor requirements is further improved.

According to an embodiment, the third point in time is indicative of a time period. That is to say that the second computing device requests the encryption key to be transmitted during the indicated time period or at the end of the indicated time period, i.e. at the third point in time.

According to an embodiment, the third point in time is a time of receipt of the request by the first computing device, i.e. the second computing device request immediate transmission of the encryption key.

According to an embodiment, the method further comprises: inhibiting transmission of the encryption key upon request, if the third point in time is prior to the first point in time. Accordingly, transmission of the encryption key is inhibited if a request for transmission of the encryption key is made too early, i.e. before the secret information is scheduled for disclosure. The inhibition can be temporary, or permanent, as a safety measure, or until receipt of a new (timely) request.

According to an embodiment, inhibiting transmission of the encryption key upon request comprises indicating the first point in time to the second computing device.

The second computing device is thus prevented from repeatedly transmitting unsuccessful requests for the encryption key prior to the first point in time, which enables both the first and second computing device to save computing resources, i.e. to use their resources more efficiently.

According to an embodiment, the method further comprises: transmitting the encryption key at the first point in time, if the third point in time is prior to the first point in time.

The second computing device is thus enabled to obtain the encryption key at the earliest possible point in time, without repeatedly sending requests, thereby improving the method's effectivity. In other words, a refused request for the encryption key results in the transmission of the key at the disclosure date, i.e. after the minimum time period during which the secret information shall not be disclosed has expired.

According to an embodiment, the method further comprises: receiving data comprising user-generated information, comparing the user-generated information with the secret information; and transmitting, to the second computing device, an indication response based on the comparison of the user-generated information with the secret information to indicate whether the user-generated information and the secret information coincide.

The secret information may, for example, be the solution to a game of chance. In that case, a user of the second computing device or any other third party may guess the content of the secret information and, subsequently, want to know whether the guess was right. Based on the response sent by the first computing device, the described method enables checking whether or not the guess is correct. In addition, the second computing device is enabled to verify the response once it has received the decryption key, thereby providing additional protection from tampering.

According to another embodiment, there is provided a data processing device comprising means for carrying out the described method.

According to another embodiment, there is provided a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the described method.

According to another embodiment, there is provided a computer-readable data carrier having stored thereon the computer program.

BRIEF DESCRIPTION OF THE DRAWING

The present invention may be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein:

Figure 1 shows a first computer system configured to perform fraud resistant transmission of predetermined secret information; figure 2 shows a flowchart of a method for fraud resistant transmission of predetermined secret information; figure 3 shows a flowchart of a method for fraud resistant comparison of predetermined secret information performed with user generated information; and figure 4 shows a second computer system configured to perform fraud resistant transmission of predetermined secret information. DETAILLED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 shows a computer system 100 configured to perform fraud resistant transmission of predetermined secret information. The system 100 comprises a first computing device 110, a second computing device 120 and a third computing device 130. One or more of the computing devices may represent a server. The first computing device 110 is coupled to the second computing device 120 via communication link 112. The communication link 112 may be a wireless communication link. Likewise, the second computing device 120 is coupled to the third computing device 130 via communication link 123.

In alternative embodiments, the third computing device 130 may be directly coupled to the first computing device 110 via communication link 123.

In the illustrated embodiment, the first computing device 110 is a provider for secret information. The secret information may be any kind of information, the content of which is unknown to the second computing device 120 and the third computing device 130. The second computing device 120 is a recipient of the secret information and uses the secret information while interacting with the third computing device. In the present embodiment, the secret information contains winning numbers of a lottery and the second computing device 120 is a lottery operator. That is to say that the second computing device 120 provides a lottery, i.e. a game of chance. The third computing device 130 acts as a participant of the lottery and guesses the right answer, i.e. the winning numbers.

During establishment or execution of the lottery, the second computing device 120 requests secret winning numbers at the first computing device via the communication link 112. The request indicates a disclosure time and/or date (hereinafter simply referred to as disclosure date) at which the winning numbers of the lottery shall be published. The disclosure date is predetermined by the second computing device 120. At the predetermined disclosure date, the first computing device 110 transmits the winning numbers to the second computing device 120 and, optionally, to the third computing device 130. In that manner, both the second and third computing devices are enabled to determine whether at least some of the winning numbers have been correctly guessed by the third computing device 130. By following the described procedure, the second computing device 120, i.e. the provider of the lottery, is disabled to fraudulently change the winning numbers and, thus, manipulate the outcome of the lottery. In order to further ensure that the winning numbers have not been altered by the third computing device during the time between request and disclosure of the winning numbers, the first computing device 110 performs a fraud resistant method for disclosing predetermined secret information, as described with reference to figure 2 or 3.

Figure 2 shows a flowchart of a method 200 for fraud resistant transmission of predetermined secret information performed by a computing device, for example by the first computing device 110.

In a first step 210, the first computing device 110 receives a request for secret information by a second computing device, for example the second computing device 120. The request received by the first computing device 110 indicates the nature of the requested secret information. In other words, the request specifies which kind of secret information is required. In the illustrated embodiment, the request indicates that a specified number of secret winning numbers is required.

The received request further indicates a disclosure date of the secret information, i.e. a point in time at which the secret information is to be made available to the requesting computing device. Additionally, or alternatively, the request may specify other recipients of the secret information. In another embodiment, the request specifies that the secret information shall be disclosed upon a respective subsequent request at or after the disclosing date, i.e. not before the disclosing date has been reached.

In response to receiving the request for secret information, the first computing device transmits, in step 220, encrypted data to the second computing device, wherein the encrypted data comprises the secret information, i.e. predetermined secret information that complies with the requested type of secret information. The transmitted data is encrypted such that the second computing device cannot derive the content of the secret information, e.g. the winning numbers, from the encrypted data. The encrypted may data further comprise a unique identifier associated with the requested information. In an optional step 215 prior to step 220, the first computing device determines the secret information depending on the requested type of secret information. In one example, in which winning numbers for a lottery have been requested, the first computing device uses a random number generator to generate the specified number of winning numbers.

The encrypted data is transmitted to the second computing device at a point in time prior to the disclosing date. In particular, the encrypted data may be transmitted immediately after the request for secret information has been received or the secret information has been generated. Alternatively, the encrypted data is transmitted to the second computing device at or before a starting point in time indicated by the received request. The starting point in time may specify the envisaged date at which the second computing time uses the secret information, e.g. at which the above described lottery commences.

In step 260, the first computing device transmits data comprising an encryption key to the second computing device at the disclosure date indicated in the request for secret information. Using the encryption key, the second computing device is enabled to decrypt the encrypted data and, thus, to effectively receive the content of the secret information. The data comprising the encryption key may further comprise an identifier associating the encryption key with the encrypted data and/or with the request for the secret information.

Alternatively, as described above, the disclosing date is indicative of a protection period of time during which the signal information shall not be disclosed. In this case, the encrypted data may not automatically be transmitted to the second computing device at the disclosing date. Rather, the encrypted data may be transmitted to the second computing device upon request after expiry of the indicated protection period of time.

Accordingly, in step 230, a request for the encryption key is received. The request may indicate a point in time at which the encryption key is to be transmitted to the requestor. Alternatively, the request may indicate a period of time, the expiry of which is to trigger the transmission of the encryption key. The request for the encryption key may further comprise the unique identifier associating the requested encryption key with the encrypted data and/or with the request for the secret information.

Subsequently, in step 240, the first computing device determines, based on the request for the secret information, whether the request for the encryption key is authorised. Step 240 may comprise determining whether the disclosing date has been reached, i.e. whether the protection period of time has been expired. Step 240 may further comprise determining whether the request is received from a computing device that is entitled to receive the secret information, i.e. whether the requesting computing device is the computing device to which the encrypted data has been sent.

Based on the determination whether the request for the encryption key is authorised, the first computing device either inhibits or performs transmission of the encryption key to the computing device requesting the encryption key. Inhibiting transmission of the encryption key may comprise indicating, to the second computing device or any other computing device requesting the encryption key, that the request for the encryption key has been rejected. Indicating that the request has been rejected may comprise indicating the reasons for rejection. Indicating the reasons for rejection may comprise indicating that the computing device requesting the encryption key is not entitled to receive the secret information or that the disclosure date has not yet been reached. The indication that the disclosing date has not been reached may further comprise an indication of the disclosing date, i.e. as to when the protection period expires.

After the transmission of the encryption key has been inhibited in step 250, the requesting computing device may repeatedly request the transmission of the encryption key. Alternatively, the encryption key is sent to the requesting computing device at the earliest possible point in time, i.e. at the disclosing date, provided that the requesting computing device is entitled of receiving the secret information.

Figure 3 shows a flowchart of a method 300 for fraud resistant comparison of predetermined secret information performed with user generated information. The method 300 is performed by a first computing device, for example by the first computing device 110. Steps 310, 315 and 320 correspond to steps 210, 215 and 220 shown in figure 2, in which secret information is requested at the first computing device and encrypted data containing the requested secret information is sent to a second computing device, e.g. to the second computing device 120. Subsequent to the transmission of the encrypted data, user generated information may be received in step 330. The user generated information may comprise information of the same type as the secret information.

In the illustrated embodiment, the user generated information comprises a guess for the winning numbers of the lottery provided by the second computing device 120. The user generated information may be received directly from a third computing device representing a participant of the lottery, e.g. from the third computing device 130 via communication link 113 shown in figure 1. In another embodiment, the user generated information may be received from the second computing device 120. In said other embodiment, the third computing device 130 may have sent the user generated information to the second computing device 120 via communication link 123 prior to the second computing device 120 sending the user generated information to the first computing device 110.

In step 340, the first computing device compares the user generated information with the secret information comprised in the transmitted encrypted data. In the illustrated embodiment, the first computing device verifies whether at least some of the winning numbers of the lottery have been guessed correctly.

Based on the comparison, the first computing device transmits, in step 350, an indication response to the second computing device 120 or to the computing device from which the user generated information has been received. The indication response indicates whether or not the user generated information coincides with the secret information, i.e. whether at least some of the winning numbers of the lottery have been guessed correctly.

Subsequently, in step 360, the encryption key is transmitted to the second computing device 120. The transmission of the encryption key may be performed automatically at the predetermined disclosure date of the secret information or upon request, as described with referend to figure 2. The second computing device 120 may then decrypt the encrypted data, retrieve the secret information and verify the previously received indication response. Alternatively or additionally, the secret information may be sent to the sent to a third computing device from which the user generated information has been received, e.g. to the third computing device 130, if said third computing device has previously received the encrypted data.

Figure 4 shows a second computer system 400 configured to perform fraud resistant transmission of predetermined secret information. The system 400 comprises a first computing device 410 and a second computing device 420, at least one of which may be a represent a server. The first computing device 410 is coupled to the second computing device 420 via communication link 412. The communication link 412 may be a wireless communication link.

In the illustrated embodiment, the first computing device 410 is both the provider and the user of the secret information, e.g. the lottery operator. The second computing device 420 is a recipient of the secret information and, in this example, a participant of the lottery.

Similar to what is described with reference to figures 1 to 3, the first computing device 410 transmits encrypted data to the second computing device 420, wherein the encrypted data comprises secret information. The first computing device 410 may perform transmission of the encrypted data responsive to receiving an indication from the second computing device 420. The received indication may indicate that the second computing device 420 intends to subsequently send user generated data to the first computing device 410, wherein the user generated information shall be compared to the secret information.

After having transmitted the encrypted data, the first computing device 410 may receive user generated data from the second computing device 420. The fist computing device 410 may reject user generated data received prior to the transmission of the encrypted data. With the transmission of the encrypted data, the first computing device 410 may further indicate to the second computing device that user generated data may be rejected if sent prior to the transmission of the encrypted data. The first computing device 410 compares the received user generated data to the secret information. The first computing device 410 may subsequently transmit an indication response to the second computing device 420, wherein the indication response may be based on the comparison, as described with reference to figure 3. The first computing device 410 may finally transmit the encryption key to the second computing device 420, as described with reference to figure 2 or 3.