Abstract: A method for a hybrid content protection architecture includes obtaining, by data processing hardware, a client-side cryptographic key and locally encrypting user content using the client-side cryptographic key. The method also includes communicating the client-side cryptographic key to a third party key manager, the third party key manager configured to store the client-side cryptographic key. In response to the third party key manager storing the client-side cryptographic key, the method includes receiving a token from the third party key manager, the token identifying the client-side cryptographic key stored at the third party key manager. The method further includes uploading the encrypted user content and the token to a server of a cloud computing platform.

Abstract: A method for providing encrypted search includes receiving, at a user device associated with a user, a search query for a keyword that appears in one or more encrypted documents stored on an untrusted storage device and accessing a count table to obtain a count of documents that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of documents. The method also includes evaluating a first portion of the DPRF and delegating a remaining second portion of the DPRF to the untrusted storage device which causes the untrusted storage device to evaluate the DPRF and access an encrypted search index associated with the documents. The untrusted storage device determines one or more encrypted documents associated with DPRF and returns, to the user device, an identifier for each encrypted document associated with the DPRF.

Abstract: A method for wrapped keys with access control predicates includes obtaining a cryptographic key for content. The method also includes encrypting the content using the cryptographic key and generating an encryption request. The encryption request requests that a third party cryptography service encrypts an encapsulation of the cryptographic key and an access control condition governing access to the content. The method also includes communicating the encryption request to the third party cryptography service. The encryption request includes the cryptographic key.

Abstract: A method for wrapped keys with access control predicates includes obtaining a cryptographic key for content. The method also includes encrypting the content using the cryptographic key and generating an encryption request. The encryption request requests that a third party cryptography service encrypts an encapsulation of the cryptographic key and an access control condition governing access to the content. The method also includes communicating the encryption request to the third party cryptography service. The encryption request includes the cryptographic key.

Abstract: A method for providing an encrypted search system includes receiving a search query for a keyword that appears in one or more encrypted emails stored on an untrusted storage device and accessing, a count table to obtain a count of unique emails within the emails that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of unique emails that include the keyword and delegating at least a portion of the DPRF to the untrusted storage device that causes the storage device to evaluate the delegated DPRF, access an encrypted search index associated with the emails, and determine one or more encrypted emails associated with the delegated DPRF based on the encrypted search index. The storage device also returns, to the user device, an identifier for each encrypted email associated with the delegated DPRF.

Abstract: A method for providing encrypted search includes receiving, at a user device associated with a user, a search query for a keyword that appears in one or more encrypted documents stored on an untrusted storage device and accessing a count table to obtain a count of documents that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of documents. The method also includes evaluating a first portion of the DPRF and delegating a remaining second portion of the DPRF to the untrusted storage device which causes the untrusted storage device to evaluate the DPRF and access an encrypted search index associated with the documents. The untrusted storage device determines one or more encrypted documents associated with DPRF and returns, to the user device, an identifier for each encrypted document associated with the DPRF.

Abstract: A method for providing encrypted search includes receiving, at a user device associated with a user, a search query for a keyword that appears in one or more encrypted documents stored on an untrusted storage device and accessing a count table to obtain a count of documents that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of documents. The method also includes evaluating a first portion of the DPRF and delegating a remaining second portion of the DPRF to the untrusted storage device which causes the untrusted storage device to evaluate the DPRF and access an encrypted search index associated with the documents. The untrusted storage device determines one or more encrypted documents associated with DPRF and returns, to the user device, an identifier for each encrypted document associated with the DPRF.

Abstract: A method for providing encrypted search includes receiving, at a user device associated with a user, a search query for a keyword that appears in one or more encrypted documents stored on an untrusted storage device and accessing a count table to obtain a count of documents that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of documents. The method also includes evaluating a first portion of the DPRF and delegating a remaining second portion of the DPRF to the untrusted storage device which causes the untrusted storage device to evaluate the DPRF and access an encrypted search index associated with the documents. The untrusted storage device determines one or more encrypted documents associated with DPRF and returns, to the user device, an identifier for each encrypted document associated with the DPRF.

Abstract: A method for providing an encrypted search system includes receiving a search query for a keyword that appears in one or more encrypted emails stored on an untrusted storage device and accessing, a count table to obtain a count of unique emails within the emails that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of unique emails that include the keyword and delegating at least a portion of the DPRF to the untrusted storage device that causes the storage device to evaluate the delegated DPRF, access an encrypted search index associated with the emails, and determine one or more encrypted emails associated with the delegated DPRF based on the encrypted search index. The storage device also returns, to the user device, an identifier for each encrypted email associated with the delegated DPRF.

Abstract: A method for wrapped keys with access control predicates includes obtaining a cryptographic key for content. The method also includes encrypting the content using the cryptographic key and generating an encryption request. The encryption request requests that a third party cryptography service encrypts an encapsulation of the cryptographic key and an access control condition governing access to the content. The method also includes communicating the encryption request to the third party cryptography service. The encryption request includes the cryptographic key.

Abstract: A method for a hybrid content protection architecture includes obtaining, by data processing hardware, a client-side cryptographic key and locally encrypting user content using the client-side cryptographic key. The method also includes communicating the client-side cryptographic key to a third party key manager, the third party key manager configured to store the client-side cryptographic key. In response to the third party key manager storing the client-side cryptographic key, the method includes receiving a token from the third party key manager, the token identifying the client-side cryptographic key stored at the third party key manager. The method further includes uploading the encrypted user content and the token to a server of a cloud computing platform.