SELECTIVE REDACTION AND ACCESS CONTROL FOR DOCUMENT SEGMENTS

1 . A method of controlling access to one or more segments of a document, the method comprising. by a system comprising a first computing device and a second computing device:

by the first computing device:

displaying, on a display, a document comprising content,

receiving, via a user interface, a user selection of a first segment of the content as marked content, and

assigning a security level to the marked content;

by the second computing device, when proximate and within a communication range of the first computing device:

generating one or more encryption keys for the marked content,

passing the one or more encryption keys to the first computing device;

by the first computing device,

using the one or more encryption keys to encrypt the marked content, yielding encrypted content, and

saving the content to a document file, in which the document file includes the marked content only in encrypted form and not in unencrypted form; and

sending either (a) one or more of the encryption keys with a document identifier for the document to a server, or (b) one or more of the encryption keys and the document file to a recipient.

2 . The method of claim 1 , further comprising:

by the second computing device, receiving the document identifier from the first computing device; and

wherein sending the one or more of the encryption keys with the document identifier for the document to the server is performed by the second computing device.

3 . The method of claim 1 , wherein receiving the document identifier from the first computing device comprises:

capturing an image of the display of the first computing device while the display is outputting a code in which the document identifier is encoded; and

decoding the code to yield the document identifier.

4 . The method of claim 1 further comprising, by the first computing device after using the one or more encryption keys, discarding the one or more encryption keys.

5 . The method of claim 1 , further comprising:

by the first computing device, while displaying the document:

receiving, via a user interface, a user selection of one more additional segments the content as additional marked content segments, and

assigning security levels to each of the additional marked content segments, wherein the assigned security levels comprise a plurality of security levels; and

by the second computing device, when generating the one or more encryption keys for the marked content, generating one or more encryption keys for each of the assigned security levels.

6 . The method of claim 5 , further comprising, by the first computing device, encrypting each of the additional marked content segments using the encryption key that was generated for the security level that is assigned to that additional marked content segment.

7 . The method of claim 1 , wherein saving the content to a document file comprises saving the marked content in encrypted form as metadata in the document file.

8 . The method of claim 1 further comprising:

sending the document file to one or more users;

assigning an access level to each of the one or more users, wherein the access level corresponds to the security level; and

sending the access levels for each of the one or more users to the remote server.

9 . A method of gaining secure access to one or more marked segments of a document, the method comprising, by a system comprising a first computing device and a second computing device:

by the first computing device, accessing a document file comprising content, in which one or more segments of the content are redacted and included only as encrypted content;

detecting that a second computing device is proximate and within a communication range of the first computing device;

sending, to a remote server, a document identifier for the document and a user credential for a user of the second computing device;

receiving, from the remote server, an encryption key; and

by the first computing device:

using the encryption key to decrypt one or more of the segments that are encrypted content, yielding one or more unmasked segments, and

causing a display of the first computing device to display the document with the one or more unmasked segments.

10 . The method of claim 9 , further comprising:

by the first computing device, receiving the user credential from the second computing device; and

wherein sending the document identifier and the user credential to the remote server is performed by the first computing device.

11 . The method of claim 9 , further comprising:

by the second computing device, receiving the document identifier from the first computing device; and

wherein sending the document identifier and the user credential to the remote server is performed by the second computing device.

12 . The method of claim 9 , wherein receiving the document identifier from the first computing device comprises, by the second computing device:

capturing an image of the display of the first computing device while the display is outputting a code in which the document identifier is encoded; and

decoding the code to yield the document identifier.

13 . The method of claim 9 , wherein:

the one or more segments of the content that are included only as encrypted content comprise a plurality of segments, each of the plurality of segments is associated with a security level, and the associated security levels comprise a plurality of security levels;

receiving the encryption key comprises receiving a plurality of encryption keys, each of which is associated with one of the security levels; and

when the first computing device uses the encryption key to decrypt any segment that has been encrypted, the system uses the encryption key having a security level matching the security level for that segment.

14 . A method of controlling access to one or more segments of a document, the method comprising. by a computing device:

displaying, on a display, a document comprising content;

receiving, via a user interface, a user selection of a first segment of the content as first marked content and a second segment of the content as second marked content;

assigning a first security level to the first marked content and a second security level to the second market content;

accessing a first encryption keys for the first security level and a second encryption key for the second security level;

using the first encryption key to encrypt the first marked content, yielding first encrypted content,

using the second encryption key to encrypt the second marked content, yielding second encrypted content;

saving the content, the first encrypted content and the second encrypted content to a document file, in which the document file includes the marked content only in encrypted form and not in unencrypted form;

identifying an access level of a recipient;

selecting, from the first encryption key and the second encryption key, a key that corresponds to the access level of the recipient; and

sending the selected encryption key and the document file to the recipient.