Patent Publication Number: US-2017364691-A1

Title: Method and System for Controlling Encryption of Information and Analyzing Information as well as Terminal

Description:
TECHNICAL FIELD 
     The present application relates to, but is not limited to, the field of communication technology. 
     BACKGROUND 
     With the rapid development of mobile Internet, smart phones have been popular at present. Social networking software based on smart phones, such as instant messaging software, has greatly changed means of communication of people. 
     However, in the communication process, some sensitive private information, such as bank card number, password, or important trade secrets that can only be known by the two sides, often needs to be sent. If the sensitive private information is sent in plaintext, there will be a security risk. 
     Therefore, in order to meet secrecy requirements of the private information involved in the instant messaging, a method of secure transmission of instant messages is required. 
     SUMMARY 
     The following is an overview of a subject described in detail herein. This overview is not intended to limit the protection scope of claims. 
     The present document provides methods, systems and terminals for controlling encryption of information and analyzing information so as to provide an encryption control and a time limitation control of information contents in instant messaging to ensure higher security and control flexibility of information transmission. 
     A method for controlling encryption of information includes: 
     determining a content of a message required to be encrypted when it is detected that the message needs to be encrypted and transmitted; 
     combining and encrypting the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message to generate an encrypted data block; and 
     sending the message in which the encrypted data block is carried. 
     In an exemplary embodiment, the method further includes the following feature: 
     combining and encrypting the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block includes: 
     performing a first encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block, and performing a second encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the method further includes the following feature: 
     combining and encrypting the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block includes: 
     combining the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message into a composite data block, and performing a third encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the method further includes the following feature: 
     combining and encrypting the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block includes: 
     performing a fourth encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block plaintext, using the composite data block plaintext as an encrypted data block to be sent. 
     In an exemplary embodiment, the method further includes the following feature: 
     performing the first encryption process on the content of the message required to be encrypted to generate the content ciphertext includes: 
     after a user has set an encryption password, generating a first encryption key according to the encryption password, and performing the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext; and when the user has not yet set an encryption password, prompting the user to set an encryption password, after the encryption password set by the user is obtained, generating the first encryption key according to the encryption password, and performing the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext; 
     performing the second encryption process on the composite data block to generate the composite data block ciphertext includes: 
     generating a second encryption key according to the encryption password, and performing the second encryption process on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the method further includes the following feature: 
     performing the third encryption process on the composite data block to generate the composite data block ciphertext includes: 
     after the user has set an encryption password, generating a third encryption key according to the encryption password, and performing the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext; and when the user has not yet set an encryption password, prompting the user to set an encryption password, after the encryption password set by the user is obtained, generating the third encryption key according to the encryption password, and performing the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the method further includes the following feature: 
     the time parameter includes one or more of the following parameters: an upper limit value of a number of views, a view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     In an exemplary embodiment, the method further includes the following feature: 
     the message is an instant message. 
     A method for analyzing information includes: 
     detecting whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message; and 
     controlling decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     In an exemplary embodiment, the method further includes the following feature: 
     controlling decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message includes: 
     when it is detected that an encrypted data block is carried in the message, prompting a user to input a decryption password, and after the decryption password input by the user is obtained, generating a first decryption key based on the decryption password, performing a first decryption process on the encrypted data block using the first decryption key, when the encrypted data block is decrypted successfully, extracting the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit indicated by the time parameter, generating a second decryption key based on the decryption password, decrypting a content ciphertext of the message contained in the encrypted data block using the second decryption key, and when the content ciphertext of the message is decrypted successfully, obtaining and displaying a content plaintext of the message. 
     In an exemplary embodiment, the method further includes the following feature: 
     controlling decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message includes: 
     when it is detected that an encrypted data block is carried in the message, prompting the user to input a decryption password, and after the decryption password input by the user is obtained, generating a third decryption key based on the decryption password, performing a third decryption process on the encrypted data block using the third decryption key, when the encrypted data block is decrypted successfully, extracting the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit, obtaining and displaying a content plaintext of the message from the decrypted data block. 
     In an exemplary embodiment, the method further includes the following feature: 
     controlling decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message includes: 
     extracting the time parameter indicating the decryption time limit of the message from the message, and when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, prompting the user to input a decryption password when the current time satisfies the decryption time limit, generating a fourth decryption key according to the decryption password after the decryption password input by the user is obtained, and performing a fourth decryption process on a ciphertext contained in the message using the fourth decryption key, and obtaining and displaying a content plaintext of the message when the ciphertext is decrypted successfully. 
     In an exemplary embodiment, the method further includes the following feature: 
     controlling decryption of the ciphertext according to the time parameter further includes: 
     when a current time does not satisfy the decryption time limit, deactivating the message. 
     In an exemplary embodiment, the method further includes the following feature: 
     the deactivation includes any one of the following: 
     directly displaying the ciphertext contained in the message; or 
     scrambling and then displaying the ciphertext contained in the message; or 
     deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     In an exemplary embodiment, the method further includes the following feature: 
     determining whether the current time satisfies the decryption time limit indicated by the time parameter includes: 
     when information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, obtaining a standard value of a current time online, comparing the standard value of the current time with a decryption validity period contained in the time parameter, and when the standard value of the current time is within the decryption validity period, determining that the current time satisfies the decryption time limit; 
     when the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, obtaining a value of a current time locally, comparing the value of the current time with the decryption validity period contained in the time parameter, and when the value of the current time is within the decryption validity period, determining that the current time satisfies the decryption time limit. 
     In an exemplary embodiment, the method further includes the following feature: 
     determining whether the current time satisfies the decryption time limit indicated by the time parameter includes: 
     when an upper limit value N of a number of views is contained in the time parameter, if N is limited, querying a view log of the message, comparing a number m of views stored in the view log with the upper limit value N of the number of views, and when the number m of views is less than the upper limit value N of the number of views, determining that a current time satisfies the decryption time limit. 
     A system for controlling encryption of information includes: 
     a first detection module configured to determine a content of a message required to be encrypted when it is detected that the message needs to be encrypted and transmitted; 
     an encryption control module configured to combine and encrypt the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message to generate an encrypted data block; and 
     a message sending module configured to send the message in which the encrypted data block is carried. 
     In an exemplary embodiment, the system further includes the following feature: 
     the encryption control module is configured to: 
     perform a first encryption process on the content of the message required to be encrypted to generate a content ciphertext; 
     combine the content ciphertext and the time parameter into a composite data block, and perform a second encryption process on the composite data block to generate a composite data block ciphertext, use the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the system further includes the following feature: 
     the encryption control module is configured to: 
     combine the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message into a composite data block, and perform a third encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the system further includes the following feature: 
     the encryption control module is configured to: perform a fourth encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combine the content ciphertext and the time parameter into a composite data block plaintext, use the composite data block plaintext as an encrypted data block to be sent. 
     In an exemplary embodiment, the system further includes the following feature: 
     the encryption control module is configured to: after a user has set an encryption password, generate a first encryption key according to the encryption password, and perform the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext; and when the user has not yet set an encryption password, prompt the user to set an encryption password, after the encryption password set by the user is obtained, generate the first encryption key according to the encryption password, and perform the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. 
     The encryption control module is configured to perform the second encryption process on the composite data block to generate the composite data block ciphertext, including: 
     generating a second encryption key according to the encryption password, and performing the second encryption process on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the system further includes the following feature: 
     the encryption control module is configured to: after the user has set an encryption password, generate a third encryption key according to the encryption password, and perform the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext; and when the user has not yet set an encryption password, prompt the user to set an encryption password, after the encryption password set by the user is obtained, generate the third encryption key according to the encryption password, and perform the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the system further includes the following feature: 
     the time parameter includes one or more of the following parameters: an upper limit value of a number of views, a view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     In an exemplary embodiment, the system further includes the following feature: 
     the message is an instant message. 
     A system for analyzing information includes: 
     a second detection module configured to detect whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message; and 
     a decryption processing module configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: when it is detected that an encrypted data block is carried in the message, prompt a user to input a decryption password, and after the decryption password input by the user is obtained, generate a first decryption key based on the decryption password, perform a first decryption process on the encrypted data block using the first decryption key, when the encrypted data block is decrypted successfully, extract the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determine whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit indicated by the time parameter, generate a second decryption key based on the decryption password, decrypt a content ciphertext of the message contained in the encrypted data block using the second decryption key, and when a content ciphertext of the message is decrypted successfully, obtain and display a content plaintext of the message. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: when it is detected that an encrypted data block is carried in the message, prompt the user to input a decryption password, and after the decryption password input by the user is obtained, generate a third decryption key based on the decryption password, perform a third decryption process on the encrypted data block using the third decryption key, when the encrypted data block is decrypted successfully, extract the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determine whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit, obtain and display a content plaintext of the message from the decrypted data block. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: extract the time parameter indicating the decryption time limit of the message from the message, and when the time parameter is extracted successfully, determine whether a current time satisfies the decryption time limit indicated by the time parameter, prompt the user to input a decryption password when the current time satisfies the decryption time limit, generate a fourth decryption key according to the decryption password after the decryption password input by the user is obtained, and perform a fourth decryption process on a ciphertext contained in the message using the fourth decryption key, and obtain and display a content plaintext of the message when the ciphertext is decrypted successfully. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: when a current time does not satisfy the decryption time limit, deactivate the message. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to deactivate the message, including: 
     directly displaying the ciphertext contained in the message; or 
     scrambling and then displaying the ciphertext contained in the message; or 
     deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: 
     when information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, obtain a standard value of a current time online, compare the standard value of the current time with a decryption validity period contained in the time parameter, and when the standard value of the current time is within the decryption validity period, determine that the current time satisfies the decryption time limit; 
     when the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, obtain a value of a current time locally, compare the value of the current time with the decryption validity period contained in the time parameter, and when the value of the current time is within the decryption validity period, determine that the current time satisfies the decryption time limit. 
     In an exemplary embodiment, the system further includes the following feature: 
     the decryption processing module is configured to: when an upper limit value N of a number of views is contained in the time parameter, if N is limited, query a view log of the message, compare a number m of views stored in the view log with the upper limit value N of the number of views, and when the number m of views is less than the upper limit value N of the number of views, determine that a current time satisfies the decryption time limit. 
     A terminal includes: 
     a first memory configured to store instructions; 
     a first processor, coupled to the first memory, configured to execute the instructions stored in the first memory, herein the first processor is configured to determine a content of a message required to be encrypted when it is detected that the message needs to be encrypted and transmitted; combine and encrypt the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message to generate an encrypted data block; and send the message in which the encrypted data block is carried. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the first processor is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including: 
     performing a first encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block, and performing a second encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the first processor is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including: 
     combining the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message into a composite data block, and performing a third encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the first processor is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including: 
     performing a fourth encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block plaintext, using the composite data block plaintext as an encrypted data block to be sent. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the first processor is configured to perform the first encryption process on the content of the message required to be encrypted to generate the content ciphertext, including: 
     after a user has set an encryption password, generating a first encryption key according to the encryption password, and performing the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext; and when the user has not yet set an encryption password, prompting the user to set an encryption password, after the encryption password set by the user is obtained, generating the first encryption key according to the encryption password, and performing the first encryption process on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext; 
     the first processor is configured to perform the second encryption process on the composite data block to generate the composite data block ciphertext, including: 
     generating a second encryption key according to the encryption password, and performing the second encryption process on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the first processor is configured to perform the third encryption process on the composite data block to generate the composite data block ciphertext, including: 
     after the user has set an encryption password, generating a third encryption key according to the encryption password, and performing the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext; and when the user has not yet set an encryption password, prompting the user to set an encryption password, after the encryption password set by the user is obtained, generating the third encryption key according to the encryption password, and performing the third encryption process on the composite data block using the third encryption key to generate the composite data block ciphertext. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the time parameter includes one or more of the following parameters: an upper limit value of a number of views, a view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the message is an instant message. 
     A terminal includes: 
     a second memory configured to store instructions; 
     a second processor coupled to the second memory, configured to execute the instructions stored in the second memory, herein the second processor is configured to detect whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message; and control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including: 
     when it is detected that an encrypted data block is carried in the message, prompting a user to input a decryption password, and after the decryption password input by the user is obtained, generating a first decryption key based on the decryption password, performing a first decryption process on the encrypted data block using the first decryption key, when the encrypted data block is decrypted successfully, extracting the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit indicated by the time parameter, generating a second decryption key based on the decryption password, decrypting a content ciphertext of the message contained in the encrypted data block using the second decryption key, and when a content ciphertext of the message is decrypted successfully, obtaining and displaying a content plaintext of the message. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including: 
     when it is detected that an encrypted data block is carried in the message, prompting the user to input a decryption password, and after the decryption password input by the user is obtained, generating a third decryption key based on the decryption password, performing a third decryption process on the encrypted data block using the third decryption key, when the encrypted data block is decrypted successfully, extracting the time parameter indicating the decryption time limit of the message from the decrypted data block, when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, and when the current time satisfies the decryption time limit, obtaining and displaying a content plaintext of the message from the decrypted data block. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including: 
     extracting the time parameter indicating the decryption time limit of the message from the message, and when the time parameter is extracted successfully, determining whether a current time satisfies the decryption time limit indicated by the time parameter, prompting the user to input a decryption password when the current time satisfies the decryption time limit, generating a fourth decryption key according to the decryption password after the decryption password input by the user is obtained, and performing a fourth decryption process on the ciphertext contained in the message using the fourth decryption key, and obtaining and displaying a content plaintext of the message when the ciphertext is decrypted successfully. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to control decryption of the ciphertext according to the time parameter, including: 
     when a current time does not satisfy the decryption time limit, deactivating the message. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to deactivate the message, including: 
     directly displaying the ciphertext contained in the message; or 
     scrambling and then displaying the ciphertext contained in the message; or 
     deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including: 
     when information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, obtaining a standard value of a current time online, comparing the standard value of a current time with a decryption validity period contained in the time parameter, and when the standard value of the current time is within the decryption validity period, determining that the current time satisfies the decryption time limit; 
     when the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, obtaining a value of a current time locally, comparing the value of the current time with the decryption validity period contained in the time parameter, and when the value of the current time is within the decryption validity period, determining that the current time satisfies the decryption time limit. 
     In an exemplary embodiment, the terminal further includes the following feature: 
     the second processor is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including: 
     when an upper limit value N of a number of views is contained in the time parameter, if N is limited, querying a view log of the message, comparing a number m of views stored in the view log with the upper limit value N of the number of views, and when the number m of views is less than the upper limit value N of the number of views, determining that a current time satisfies the decryption time limit. 
     A computer readable storage medium having computer-executable instructions stored therein used to execute the methods described above. 
     In the methods, systems and terminals for controlling encryption of information and analyzing information provided by embodiments of the present disclosure, a sending end of an instant message needs to combine and transmit the content of the message to be encrypted and the time parameter indicating the decryption time limit of the message. After receiving the message carrying the ciphertext, a receiving end of an instant message decrypts the message, determines whether the current time is within the decryption validity period of the message, and decrypts the message if it is within the decryption validity period, and deactivates the message if it is not within the decryption validity period. The embodiments of the present disclosure can provide encryption control and time limit control for the information content in the instant communication to ensure higher security and control flexibility for information transmission. 
     Upon reading and understanding the accompanying drawings and detailed description, other aspects can be understood. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a flow chart of a method for controlling encryption of information in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a flow chart of a method for analyzing information in accordance with an embodiment of the present disclosure. 
         FIG. 3  is a block diagram of a system for controlling encryption of information in accordance with an embodiment of the present disclosure. 
         FIG. 4  is a block diagram of a system for analyzing information in accordance with an embodiment of the present disclosure. 
         FIG. 5  is a block diagram of a terminal capable of controlling encryption of information in accordance with an embodiment of the present disclosure. 
         FIG. 6  is a block diagram of a terminal capable of analyzing information in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present document will be described in detail below in conjunction with accompanying drawings. It should be noted that the embodiments in the present disclosure and features in the embodiments can be combined with each other arbitrarily without conflict. 
     As shown in  FIG. 1 , an embodiment of the present disclosure provides a method for controlling encryption of information including the following steps. 
     At S 110 , a content of a message required to be encrypted is determined when it is detected that the message needs to be encrypted and transmitted. 
     At S 120 , the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message are combined and encrypted to generate an encrypted data block. 
     At S 130 , the message is sent, and the encrypted data block is carried in the message. 
     The method may further include the following features. 
     The message is an instant message. 
     The combining step of S 120  includes: performing a first encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block, and performing a second encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The combining step of S 120  includes: combining the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message into a composite data block, and performing a third encryption process on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The combining step of S 120  includes: performing a fourth encryption process on the content of the message required to be encrypted to generate a content ciphertext; and combining the content ciphertext and the time parameter into a composite data block plaintext, using the composite data block plaintext as an encrypted data block to be sent. 
     Performing the first encryption process on the content of the message required to be encrypted to generate the content ciphertext includes following operations. 
     After a user has set an encryption password, a first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. When the user has not yet set an encryption password, the user is prompted to set an encryption password. After the encryption password set by the user is obtained, the first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. 
     Performing the second encryption process on the composite data block to generate the composite data block ciphertext includes: generating a second encryption key according to the encryption password, and performing the second encryption process on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     The first encryption key and the second encryption key may be the same or different. 
     An encryption algorithm for the first encryption process and an encryption algorithm for the second encryption process may be the same or different. 
     Performing the third encryption process on the composite data block to generate the composite data block ciphertext includes following operations. 
     After the user has set an encryption password, a third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block using the third encryption key to generate the composite data block ciphertext. When the user has not yet set an encryption password, the user is prompted to set an encryption password. After the encryption password set by the user is obtained, the third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block using the third encryption key to generate the composite data block ciphertext. 
     Performing the fourth encryption process on the content of the message required to be encrypted to generate the content ciphertext includes following operations. 
     After the user has set an encryption password, a fourth encryption key is generated according to the encryption password, and the fourth encryption process is performed on the content of the message required to be encrypted using the fourth encryption key to generate the content ciphertext. When the user has not yet set an encryption password, the user is prompted to set an encryption password. After the encryption password set by the user is obtained, the fourth encryption key is generated according to the encryption password, and the fourth encryption process is performed on the content of the message required to be encrypted using the fourth encryption key to generate the content ciphertext. 
     The time parameter includes one or more of the following parameters: an upper limit value of the number of views, a view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     The upper limit value of the number of views can be limited or unlimited. 
     The view validity period can be expressed by a starting time and an effective duration, or can also be expressed by a starting time and a termination time. 
     Whether the receiving end needs to calibrate a time online means that whether the receiving end needs to obtain standard time online when viewing information. Due to difference between the local time of the receiving end and the standard time, the receiving end can improve accuracy of time limit control by obtaining the standard time online. 
     As shown in  FIG. 2 , an embodiment of the present disclosure provides a method for analyzing information including the following steps. 
     At S 210 , it is detected whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message. 
     At S 220 , decryption of the ciphertext is controlled according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     The method of analyzing the information may further include the following features: 
     The message is an instant message. 
     The time parameter includes one or more of the following parameters: an upper limit value of the number of views, a view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     The upper limit value of the number of views can be limited or unlimited. 
     The view validity period can be expressed by a starting time and an effective duration, or can also be expressed by a starting time and a termination time. 
     Whether the receiving end needs to calibrate a time online means that whether the receiving end needs to obtain standard time online when viewing information. Due to difference between the local time of the receiving end and the standard time, the receiving end can improve accuracy of time limit control by obtaining the standard time online. 
     The time parameter includes a marker character; when the message is analyzed, the time parameter is extracted according to the marker character. 
     In an embodiment, the step of S 220  include following operations. 
     When it is detected that an encrypted data block is carried in the message, a user is prompted to input a decryption password. And after the decryption password input by the user is obtained, a first decryption key is generated based on the decryption password, a first decryption process is performed on the encrypted data block using the first decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block. If the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit indicated by the time parameter, a second decryption key is generated based on the decryption password, a content ciphertext of the message contained in the encrypted data block is decrypted using the second decryption key. If a content ciphertext of the message is decrypted successfully, a content plaintext of the message is obtained and displayed. 
     The first decryption key and the second decryption key may be the same or different. 
     A decryption algorithm for the first decryption process and a decryption algorithm for the second decryption process may be the same or different. 
     In an embodiment, the step of S 220  include following operations. 
     When it is detected that an encrypted data block is carried in the message, the user is prompted to input a decryption password. After the decryption password input by the user is obtained, a third decryption key is generated based on the decryption password, a third decryption process is performed on the encrypted data block using the third decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block. If the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit, a content plaintext of the message is obtained from the decrypted data block and is displayed. 
     In an embodiment, the step of S 220  include following operations. 
     The time parameter indicating the decryption time limit of the message is extracted from the message. If the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. The user is prompted to input a decryption password when the current time satisfies the decryption time limit. A fourth decryption key is generated according to the decryption password after the decryption password input by the user is obtained, and a fourth decryption process is performed on a ciphertext contained in the message using the fourth decryption key. A content plaintext of the message is obtained and displayed if the ciphertext is decrypted successfully. 
     Determining whether the current time satisfies the decryption time limit indicated by the time parameter includes the following operations. 
     When information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, a standard value of a current time online is obtained, the standard value of the current time is compared with a decryption validity period contained in the time parameter. If the standard value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. When the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, a value of a current time is obtained locally, the value of the current time is compared with the decryption validity period contained in the time parameter. If the value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. 
     Determining whether the current time satisfies the decryption time limit indicated by the time parameter includes the following operations. 
     When an upper limit value N of the number of views is contained in the time parameter, if N is limited, a view log of the message is queried, the number m of views stored in the view log is compared with the upper limit value N of the number of views. If the number m of views is less than the upper limit value N of the number of views, it is determined that a current time satisfies the decryption time limit. 
     Querying the view log of the message includes: querying the view log of the message locally or querying the view log of the message from the server via the network, herein the server is used to collect and save the view log of the message having a limit of the number of views. 
     Controlling decryption of the ciphertext according to the time parameter further includes: when a current time does not satisfy the decryption time limit, deactivating the message. 
     The deactivation includes any of the following: directly displaying the ciphertext contained in the message; or scrambling and then displaying the ciphertext contained in the message; or deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     As shown in  FIG. 3 , an embodiment of the present disclosure provides a system for controlling encryption of information, including a first detection module  31 , an encryption control module  32  and a message sending module  33 . 
     The first detection module  31  is configured to determine a content of a message required to be encrypted when it is detected that the message needs to be encrypted and transmitted. 
     The encryption control module  32  is configured to combine and encrypt the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message to generate an encrypted data block. 
     The message sending module  33  is configured to send the message in which the encrypted data block is carried. 
     The system for controlling encryption of information may further include the following features. 
     The encryption control module  32  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     A first encryption process is performed on the content of the message required to be encrypted to generate a content ciphertext; and the content ciphertext and the time parameter are combined into a composite data block. A second encryption process is performed on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The encryption control module  32  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     The content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message are combined into a composite data block. A third encryption process is performed on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The encryption control module  32  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     A fourth encryption process is performed on the content of the message required to be encrypted to generate a content ciphertext. The content ciphertext and the time parameter are combined into a composite data block plaintext, using the composite data block plaintext as an encrypted data block to be sent. 
     The encryption control module  32  is configured to perform the first encryption process on the content of the message required to be encrypted to generate the content ciphertext, including following operations. 
     After a user has set an encryption password, a first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. When the user has not yet set an encryption password, the user is prompted to set an encryption password. After the encryption password set by the user is obtained, the first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. 
     The encryption control module  32  is configured to perform the second encryption process on the composite data block to generate the composite data block ciphertext, including following operations. 
     A second encryption key is generated according to the encryption password, and the second encryption process is performed on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     The encryption control module  32  is configured to encrypt the composite data block to generate the composite data block ciphertext, including following operations. 
     After the user has set an encryption password, a third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block using the third encryption key to generate the composite data block ciphertext. When the user has not yet set an encryption password, the user is prompted to set an encryption password. After the encryption password set by the user is obtained, the third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block using the third encryption key to generate the composite data block ciphertext. 
     The time parameter includes one or more of the following parameters: an upper limit value of the number of views, view validity period, and a parameter indicating whether a receiving end needs to calibrate a time online. 
     The message is an instant message. 
     As shown in  FIG. 4 , an embodiment of the present disclosure further provides a system for analyzing information, including a second detection module  41  and a decryption processing module  42 . 
     The second detection module  41  is configured to detect whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message. 
     The decryption processing module  42  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     The system for analyzing the information may further include the following features. 
     The decryption processing module  42  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     When it is detected that an encrypted data block is carried in the message, a user is prompted to input a decryption password. After the decryption password input by the user is obtained, a first decryption key is generated based on the decryption password, a first decryption process is performed on the encrypted data block using the first decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block. If the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit indicated by the time parameter, a second decryption key is generated based on the decryption password, a content ciphertext of the message contained in the encrypted data block is decrypted using the second decryption key. If the content ciphertext of the message is decrypted successfully, a content plaintext of the message is obtained and displayed. 
     The decryption processing module  42  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     When it is detected that an encrypted data block is carried in the message, the user is prompted to input a decryption password. After the decryption password input by the user is obtained, a third decryption key is generated based on the decryption password, a third decryption process is performed on the encrypted data block using the third decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block. If the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit, a content plaintext of the message is obtained from the decrypted data block and displayed. 
     The decryption processing module  42  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     The time parameter indicating the decryption time limit of the message is extracted from the message, and if the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter, the user is prompted to input a decryption password when the current time satisfies the decryption time limit. A fourth decryption key is generated according to the decryption password after the decryption password input by the user is obtained, and a fourth decryption process is performed on the ciphertext contained in the message using the fourth decryption key, and a content plaintext of the message is obtained and displayed if the ciphertext is decrypted successfully. 
     The decryption processing module  42  is further configured to: when the current time does not satisfy the decryption time limit, deactivate the message. 
     The decryption processing module  42  is configured to deactivate the message, including: directly displaying the ciphertext contained in the message; or scrambling and then displaying the ciphertext contained in the message; or deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     The decryption processing module  42  is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including following operations. 
     When information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, a standard value of a current time is obtained, the standard value of the current time is compared with a decryption validity period contained in the time parameter, and if the standard value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. When the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, a value of a current time is obtained locally, the value of the current time is compared with the decryption validity period contained in the time parameter, and if the value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. 
     The decryption processing module  42  is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including following operations. 
     When an upper limit value N of the number of views is contained in the time parameter, if N is limited, a view log of the message is queried, the number m of views stored in the view log is compared with the upper limit value N of the number of views, and if the number m of views is less than the upper limit value N of the number of views, it is determined that a current time satisfies the decryption time limit. 
     As shown in  FIG. 5 , an embodiment of the present disclosure provides a terminal, including a first memory  51  and a first processor  52 . 
     The first memory  51  is configured to store instructions. 
     The first processor  52  is coupled to the first memory  51 , the first processor  52  is configured to execute the instructions stored in the first memory  51 , herein the first processor  52  is configured to determine a content of a message required to be encrypted when it is detected that the message needs to be encrypted and transmitted; combine and encrypt the content of the message required to be encrypted and a time parameter indicating a decryption time limit of the message to generate an encrypted data block; and send the message in which the encrypted data block is carried. 
     The terminal may further include the following features. 
     The first processor  52  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     A first encryption process is performed on the content of the message required to be encrypted to generate a content ciphertext; and the content ciphertext and the time parameter are combined into a composite data block. A second encryption process is performed on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The first processor  52  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     The content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message are combined into a composite data block, and a third encryption process is performed on the composite data block to generate a composite data block ciphertext, using the composite data block ciphertext as an encrypted data block to be sent. 
     The first processor  52  is configured to combine and encrypt the content of the message required to be encrypted and the time parameter indicating the decryption time limit of the message to generate the encrypted data block, including following operations. 
     A fourth encryption process is performed on the content of the message required to be encrypted to generate a content ciphertext; and the content ciphertext and the time parameter are combined into a composite data block plaintext, using the composite data block plaintext as an encrypted data block to be sent. 
     The first processor  52  is configured to perform the first encryption process on the content of the message required to be encrypted to generate the content ciphertext, including following operations. 
     After a user has set an encryption password, a first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. When the user has not yet set an encryption password, the user is prompted to set the encryption password. After the encryption password set by the user is obtained, the first encryption key is generated according to the encryption password, and the first encryption process is performed on the content of the message required to be encrypted using the first encryption key to generate the content ciphertext. 
     The first processor  52  is configured to perform the second encryption process on the composite data block to generate the composite data block ciphertext, including: generating a second encryption key according to the encryption password, and performing the second encryption process on the composite data block using the second encryption key to generate the composite data block ciphertext. 
     The first processor  52  is configured to perform the third encryption process on the composite data block to generate the composite data block ciphertext, including following operations. 
     After the user has set an encryption password, a third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block using the third encryption key to generate the composite data block ciphertext. When the user has not yet set an encryption password, the user is prompted to set the encryption password. After the encryption password set by the user is obtained, the third encryption key is generated according to the encryption password, and the third encryption process is performed on the composite data block ciphertext required to be encrypted using the third encryption key to generate the composite data block ciphertext. 
     The time parameter includes one or more of the following parameters: an upper limit value of the number of views, a view validity period, and a parameter indicating whether a receiving end to calibrate a time online. 
     The message is an instant message. 
     As shown in  FIG. 6 , an embodiment of the present disclosure further provides a terminal, including a second memory  61  and a second processor  62 . 
     The second memory  61  is configured to store instructions. 
     The second processor  62  is coupled to the second memory  61 , the second processor  62  is configured to execute the instructions stored in the second memory, herein the second processor  62  is configured to detect whether a ciphertext and a time parameter indicating a decryption time limit of a message are carried in the message; and control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message. 
     The terminal further includes the following features. 
     The second processor  62  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     When it is detected that an encrypted data block is carried in the message, a user is prompted to input a decryption password. After the decryption password input by the user is obtained, a first decryption key is generated based on the decryption password, a first decryption process is performed on the encrypted data block using the first decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block, if the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit indicated by the time parameter, a second decryption key is generated based on the decryption password, a content ciphertext of the message contained in the encrypted data block is decrypted using the second decryption key. If the content ciphertext of the message is decrypted successfully, a content plaintext of the message is obtained and displayed. 
     The second processor  62  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     When it is detected that an encrypted data block is carried in the message, the user is prompted to input a decryption password. After the decryption password input by the user is obtained, a third decryption key is generated based on the decryption password, a third decryption process is performed on the encrypted data block using the third decryption key. If the encrypted data block is decrypted successfully, the time parameter indicating the decryption time limit of the message is extracted from the decrypted data block, if the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter. When the current time satisfies the decryption time limit, a content plaintext of the message is obtained from the decrypted data block and is displayed. 
     The second processor  62  is configured to control decryption of the ciphertext according to the time parameter when it is detected that the ciphertext and the time parameter indicating the decryption time limit of the message are carried in the message, including following operations. 
     The time parameter indicating the decryption time limit of the message is extracted from the message, and if the time parameter is extracted successfully, it is determined whether a current time satisfies the decryption time limit indicated by the time parameter, the user is prompted to input a decryption password when the current time satisfies the decryption time limit. A fourth decryption key is generated according to the decryption password after the decryption password input by the user is obtained, and a fourth decryption process is performed on a ciphertext contained in the message using the fourth decryption key, and a content plaintext of the message is obtained and displayed if the ciphertext is decrypted successfully. 
     The second processor  62  is configured to control decryption of the ciphertext according to the time parameter, including: when a current time does not satisfy the decryption time limit, deactivating the message. 
     The second processor  62  is configured to deactivate the message, including: directly displaying the ciphertext contained in the message; or scrambling and then displaying the ciphertext contained in the message; or deleting the ciphertext in the message and displaying prompt information for prompting the user that a view validity period of the message has expired. 
     The second processor  62  is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including following operations. 
     When information indicating that a receiving end needs to calibrate a time online is contained in the time parameter, a standard value of a current time online is obtained, the standard value of the current time is compared with a decryption validity period contained in the time parameter, and if the standard value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. When the information indicating that the receiving end does not need to calibrate a time online is contained in the time parameter, a value of a current time locally is obtained, the value of the current time is compared with the decryption validity period contained in the time parameter, and if the value of the current time is within the decryption validity period, it is determined that the current time satisfies the decryption time limit. 
     The second processor  62  is configured to determine whether the current time satisfies the decryption time limit indicated by the time parameter, including following operations. 
     When an upper limit value N of the number of views is contained in the time parameter, if N is limited, a view log of the message is queried, the number m of views stored in the view log is compared with the upper limit value N of the number of views, and if the number m of views is less than the upper limit value N of the number of views, it is determined that a current time satisfies the decryption time limit. 
     In the methods, systems and terminals for encrypting and analyzing information provided by the embodiments of the present disclosure, a sending end of an instant message needs to combine and transmit the content of the message to be encrypted and the time parameter indicating the decryption time limit of the message. After receiving the message carrying the ciphertext, a receiving end of the instant message decrypts the message, determines whether the current time is within the decryption validity period of the message, and decrypts the message if it is within the decryption validity period, and deactivates the message if it is not within the decryption validity period. The embodiments of the present disclosure can provide encryption control and time limit control for the information content in the instant communication to ensure higher security and control flexibility for information transmission. 
     Those skilled in the art can understand that all or parts of steps of the above-mentioned embodiments can be implemented using computer program processes. The computer program can be stored in one computer readable storage medium. The computer program is executed on the corresponding hardware platform (e.g., system, equipment, apparatus, device, etc), and when the computer program is executed, one or a combination of steps of the method embodiments is included. 
     Alternatively, all or parts of steps of the above-mentioned embodiments can also be implemented using integrated circuits, these steps can be fabricated into individual integrated circuit modules respectively, or multiple modules or steps thereof are fabricated into a single integrated circuit to implement. 
     Devices/functional modules/functional units in the embodiments described above can be implemented using a general-purpose computing device. They can be centralized on a single computing device, or distributed in a network which consists of multiple computing devices. 
     Devices/functional modules/functional units in the embodiments described above, when implemented in the form of software functional module and sold or used as separate products, can be stored in one computer readable storage medium. The above-mentioned computer readable storage medium can be read-only memory, disk or compact disc, etc. 
     INDUSTRIAL APPLICABILITY 
     The embodiments of the present disclosure can provide encryption control and time limit control for the information content in the instant communication to ensure higher security and control flexibility for information transmission.