Method and system for sender-controlled messaging and content sharing

Abstract

An access-control device that controls access to encrypted messages. During operation, the access-control device can receive an access key for a corrupted message, and can receive a cover message digest associated with the corrupted message. The access-control device stores the access key in association with the cover message digest, and stores the cover message digest in a block chain. A respective block of the block chain includes at least one cover message digest, and a hash value of a previous block of the block chain.

What is claimed is: 
     
         1 . A method for facilitating anonymous access to an external service, comprising:
 receiving a request for accessing the external service from a user;   receiving identifying information of a target user and a piece of content for the target user;   allocating an anonymous user identifier associated with the external service to the user; and   sending the piece of content to the target user via the external service based on the anonymous user identifier.   
     
     
         2 . The method of  claim 1 , wherein the piece of content includes one or more of:
 a message;   a document; and   a media file.   
     
     
         3 . The method of  claim 1 , wherein sending the piece of content to the target user further comprises sending a message comprising a link via the external service, wherein the message indicates that an anonymous user intends to send a piece of content to the target user, and wherein clicking the link provides the piece of content to the target user. 
     
     
         4 . The method of  claim 1 , further comprising:
 receiving authenticating information associated with the user for the external service; and   in response to successfully authenticating the user with the external service, revealing identity of the user to the target user.   
     
     
         5 . The method of  claim 4 , further comprising:
 determining a messaging mechanism for the target user sending a message to the user via the external service; and   allowing direct message exchange between the user and the target user via the messaging mechanism based on the successful authentication.   
     
     
         6 . The method of  claim 4 , wherein the authenticating information includes one or more of:
 a user name;   an email address;   a phone number; and   login credentials.   
     
     
         7 . The method of  claim 1 , wherein the external service is a messaging service based on one or more of:
 a short message service (SMS) message;   an instant messaging (IM) message; and   a social media message or post.   
     
     
         8 . The method of  claim 1 , further comprising selecting the piece of content from a local device of the user or a network folder associated with the user. 
     
     
         9 . The method of  claim 1 , further comprising receiving a rule indicating one or more of:
 a timeline during which the piece of content is available; and   whether the piece of content is forwardable from the target user.   
     
     
         10 . The method of  claim 1 , further comprising receiving, from a device of the target user, a notification indicating one or more actions performed on the piece of content. 
     
     
         11 . A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for facilitating anonymous access to an external service, the method comprising:
 receiving a request for accessing the external service from a user;   receiving identifying information of a target user and a piece of content for the target user;   allocating an anonymous user identifier associated with the external service to the user; and   sending the piece of content to the target user via the external service based on the anonymous user identifier.   
     
     
         12 . The storage medium of  claim 11 , wherein the piece of content includes one or more of:
 a message;   a document; and   a media file.   
     
     
         13 . The storage medium of  claim 11 , wherein sending the piece of content to the target user further comprises sending a message comprising a link via the external service, wherein the message indicates that an anonymous user intends to send a piece of content to the target user, and wherein clicking the link provides the piece of content to the target user. 
     
     
         14 . The storage medium of  claim 11 , wherein the method further comprises:
 receiving authenticating information associated with the user for the external service; and   in response to successfully authenticating the user with the external service, revealing identity of the user to the target user.   
     
     
         15 . The storage medium of  claim 14 , wherein the method further comprises:
 determining a messaging mechanism for the target user sending a message to the user via the external service; and   allowing direct message exchange between the user and the target user via the messaging mechanism based on the successful authentication.   
     
     
         16 . The storage medium of  claim 14 , wherein the authenticating information includes one or more of:
 a user name;   an email address;   a phone number; and   login credentials.   
     
     
         17 . The storage medium of  claim 11 , wherein the external service is a messaging service based on one or more of:
 a short message service (SMS) message;   an instant messaging (IM) message; and   a social media message or post.   
     
     
         18 . The storage medium of  claim 11 , wherein the method further comprises selecting the piece of content from a local device of the user or a network folder associated with the user. 
     
     
         19 . The storage medium of  claim 11 , wherein the method further comprises receiving a rule indicating one or more of:
 a timeline during which the piece of content is available; and   whether the piece of content is forwardable from the target user.   
     
     
         20 . The storage medium of  claim 11 , wherein the method further comprises receiving, from a device of the target user, a notification indicating one or more actions performed on the piece of content.