8. A system for encrypting information using a computational tag, the system comprising: a mobile electronic device; and a computer-readable storage medium comprising one or more programming instructions that, when executed, cause the mobile electronic device to: detect a computational tag within a near field communication range of the mobile electronic device, identify a document to be encrypted by: in response to detecting the computational tag, causing a storage application on the mobile electronic device to open and one or more stored documents to be displayed, and receiving a selection of one of the stored documents, encrypt the document and generating an unencrypted key that may be used to decrypt the encrypted document, transmit the unencrypted key to the computational tag, receive, from the computational tag, an encrypted key, wherein the encrypted key comprises an encrypted version of the unencrypted key, and store the encrypted key in a memory of the mobile electronic device and not retaining the unencrypted key in the memory of the mobile electronic device.
8. A system for encrypting information using a computational tag, the system comprising: a mobile electronic device; and a computer-readable storage medium comprising one or more programming instructions that, when executed, cause the mobile electronic device to: detect a computational tag within a near field communication range of the mobile electronic device, identify a document to be encrypted by: in response to detecting the computational tag, causing a storage application on the mobile electronic device to open and one or more stored documents to be displayed, and receiving a selection of one of the stored documents, encrypt the document and generating an unencrypted key that may be used to decrypt the encrypted document, transmit the unencrypted key to the computational tag, receive, from the computational tag, an encrypted key, wherein the encrypted key comprises an encrypted version of the unencrypted key, and store the encrypted key in a memory of the mobile electronic device and not retaining the unencrypted key in the memory of the mobile electronic device. 9. The system of claim 8 , wherein the one or more programming instructions that, when executed, cause the mobile electronic device to detect the computational tag comprise one or more programming instructions that, when executed, cause the mobile electronic device to detect the computational tag when the tag is in physical contact with the mobile electronic device.