Secure information transfer via bar codes

1. A method of providing a document using a secure bar code, the method comprising:

encrypting, via a computing device including a bar code reader, the document to generate an encrypted document;

mixing together, via the computing device, bits for a security credential with bits for the encrypted document to generate a set of mixed bits having a predetermined order, wherein the security credential is for decrypting the encrypted document;

providing, to the computing device, scrambling information that specifies the predetermined order, where the scrambling information is shared between a portion of the computing device and the bar code reader;

inserting, via the computing device, the set of mixed bits into the secure bar code; and

outputting the secure bar code, wherein the computing device knows the predetermined order and is configured to read the secure bar code using the bar code reader according to the received scrambling information, un-mix the mixed bits based on the predetermined order, and decrypt the encrypted document with the security credential.

2. The method of claim 1 , further comprising:

selecting the predetermined order from a plurality of predetermined orders, wherein:

the predetermined orders are respectively associated with marker positions that are included in a plurality of marker positions,

the marker positions are positions in the secure bar code, and each of the marker positions uniquely indicates use of one of the predetermined orders in the secure bar code; and

inserting a marker at one of the marker positions that is associated with the predetermined order.

3. The method of claim 2 , wherein the computing device knows the predetermined order based on the marker position of the marker.

4. The method of claim 1 , wherein the secure bar code is a two-dimensional bar code or a three-dimensional bar code.

5. A method of providing a document using a secure bar code, the method comprising:

encrypting, via a computing device including a bar code reader, the document to generate an encrypted document;

mixing together, via the computing device, the encrypted document and a network address into the secure bar code to generate a set of mixed bits having a predetermined order, wherein the network address identifies a network location of a security credential for decrypting the encrypted document;

providing, to the computing device, scrambling information that specifies the predetermined order, where the scrambling information is shared between a portion of the computing device and the bar code reader; and

outputting the secure bar code on a display, wherein the bar code reader of the computing device is configured to read the secure bar code using the bar code reader, un-mix the network address according to the received scrambling information, access the network location based on the network address to retrieve the security credential, and decrypt the encrypted document with the security credential.

6. The method of claim 5 , wherein the network location is password protected.

7. A method of providing a document using a secure bar code, the method comprising:

encrypting the document to generate an encrypted document;

inserting the encrypted document into the secure bar code;

mixing together bits for a security credential with bits for the encrypted document to generate a set of mixed bits having a predetermined order, where the security credential is for decrypting the encrypted document, and where inserting the encrypted document into the secure bar code includes inserting the set of mixed bits into the secure bar code;

sharing, between a portion of the computing device and a bar code reader of the computing device, the scrambling information that specifies the predetermined order;

outputting, via the computing device, the secure bar code for display; and

outputting, via the computing device, a masking image masking the secure bar code, wherein:

the masking image masks the display of the secure bar code according to a masking technique, and

the computing device is configured to read the secure bar code and the masking image using the bar code reader, separate the masking image from the secure bar code based on the masking technique to isolate the secure bar code, extract the encrypted document from the secure bar code according to the received scrambling information, and decrypt the encrypted document with the security credential.

8. The method of claim 7 , wherein the masking technique is a shared secret between the computing device and the bar code reader.

9. The method of claim 7 , further comprising:

receiving the masking image from a second computing device via a network; and

inserting a network address for the masking image in the secure bar code.

10. The method of claim 7 , further comprising:

selecting the predetermined order from a plurality of predetermined orders, wherein:

the predetermined orders are respectively associated with marker positions that are included in a plurality of marker positions,

the marker positions are positions in the secure bar code, and each of the marker positions uniquely indicates use of one of the

predetermined orders in the secure bar code; and

inserting a marker at one of the marker positions that is associated with the predetermined order.

11. The method of claim 10 , wherein the computing device knows the predetermined order based on the marker position of the marker.

12. The method of claim 7 , further comprising:

inserting the document in the secure bar code includes inserting, via the computing device, the encrypted document and a network address into the secure bar code,

the network address identifies a network location of a security credential for decrypting the encrypted document, and

the bar code reader is configured access the network location based on the network address to retrieve the security credential, and decrypt the encrypted document with the security credential.

13. The method of claim 12 , wherein the network location is a password protected network location.