Secure point of sale presentation of a barcode at an information handling system display

1. A method for performing a point-of-sale transaction, the method comprising:

sensing a condition specific at a point-of-sale location with a portable information handling system located at the point-of-sale location, the condition including at least a GPS position;

applying a valued derived from the sensed condition to encrypt an account identifier in a barcode;

presenting the bar code at a display of the portable information handling system;

reading the barcode from the display with a barcode reader at the point-of-sale location;

determining the sensed condition at the point-of-sale location independent of the portable information handling system;

decrypting the barcode with the value derived from the sensed condition at the point-of-sale location; and

applying the account identifier from the barcode to perform the point-of-sale transaction.

2. The method of claim 1 wherein sensing a condition at a point of sale location further comprises:

determining a location with a GPS receiver integrated in the portable information handling system; and

selecting a predetermined portion of the location as an encryption key to encrypt the account identifier.

3. The method of claim 1 wherein sensing a condition at a point of sale location further comprises:

determining a time from a publicly accessible time source; and

selecting a predetermined portion of the time as an encryption key to encrypt the account identifier.

4. The method of claim 1 wherein sensing a condition at a point of sale location further comprises:

reading a key with a near field communication device associated with the barcode reader, the key unique to the point of sale location; and

applying the key as an encryption key to encrypt the account identifier.

5. The method of claim 1 wherein sensing a condition at a point of sale location further comprises:

reading a barcode placed proximate the barcode reader; and

applying information read from the barcode to encrypt the account identifier, the information unique to the point of sale location.

6. The method of claim 5 wherein applying information read from the barcode further comprises:

reading a key embedded in the barcode; and

applying the key to encrypt the account identifier.

7. The method of claim 5 wherein applying information read from the barcode further comprises:

reading a network address embedded in the barcode;

retrieving a key from the network address;

applying the key to encrypt the account identifier; and

retrieving the key from the network address to the barcode reader to decrypt the account identifier.

8. The method of claim 1 further comprising:

embedding a time of generation of the barcode in the barcode; and

invalidating the barcode at the barcode reader if the embedded time of generation of the barcode is greater than a predetermined time from a current time.

9. The method of claim 1 further comprising:

embedding transaction information in the barcode, the transaction information associated with previous transactions of the account identifier; and

invalidating the barcode with the barcode reader if the previous transactions do not match previous transactions stored at the barcode reader.

10. A point of sale transaction system comprising:

a portable information handling system having a processor operable to execute instructions to process information, memory interfaced with the processor and operable to store the information and a display interfaced with the processor and operable to present the information as visual images;

a barcode generator stored in the memory and operable to execute on the processor to apply the information to generate a barcode for presentation at the display;

a sensor integrated in the portable information handling system and operable to sense publicly accessible information at a point of sale, the publicly accessible information unique to the point of sale and including at least a GPS position;

a transaction engine stored in the memory and operable to execute on the processor to embed an account identifier and the publicly accessible information in a barcode generated by the barcode generator, the barcode presented at the display, the transaction engine encrypting at least the account identifier by using at least a portion of the publicly accessible information as an encryption key; and

a barcode reader separate from the mobile information handling system and operable to read the barcode from the display, extract the account identifier and apply the publicly accessible information to validate a point-of-sale transaction, the barcode reader decrypting the account identifier with the publicly accessible information used as a decryption key.

11. The point of sale transaction system of claim 10 wherein the publicly accessible information comprises a time at which the barcode generator generates the barcode, the barcode reader operable to invalidate use of the account identifier if the time at which the barcode generator generates the barcode is greater than a predetermined amount from a current time at the barcode reader.

12. The point of sale transaction system of claim 10 wherein the publicly accessible information comprises a time associated with generation of the barcode, the barcode generator operable to apply the time to encrypt the account identifier in the barcode, the barcode reader applying a time at which the barcode is read to decrypt the account identifier.

13. The point of sale transaction system of claim 10 wherein the publicly accessible information comprises a GPS position of the mobile information handling system at the generation of the barcode, the barcode reader operable to invalidate use of the account identifier if the position at which the barcode generator generates the barcode is greater than a predetermined distance from the position of the barcode reader.

14. The point of sale transaction system of claim 10 wherein the publicly accessible information comprises a GPS position associated with generation of the barcode, the barcode generator operable to apply the GPS position to encrypt the account identifier in the barcode, the barcode reader applying a GPS position at which the barcode is read to decrypt the account identifier.

15. The point of sale transaction system of claim 10 wherein the publicly accessible information comprises a most recent transaction associated with the account identifier at the generation of the barcode, the barcode reader operable to access the account identifier and to verify the most recent transaction to validate the point of sale transaction.

16. The point of sale transaction system of claim 10 wherein the portable information handling system comprises a mobile telephone.

17. A method for restricting use of a transaction barcode, the method comprising:

sensing a condition at a mobile telephone, the condition including at least a GPS position determined independently at the mobile telephone;

generating a transaction barcode at the mobile telephone, the transaction barcode including an account identifier and the sensed condition, the sensed condition used as an encryption key to encrypt the transaction barcode;

presenting the transaction barcode at a display of the mobile telephone;

reading the transaction barcode from the display of the mobile telephone with a barcode reader; and

invalidating the transaction if the sensed condition included in the bar code fails to match the sensed condition at the barcode reader.

18. The method of claim 17 wherein the sensed condition comprises a GPS position.

19. The method of claim 17 wherein the sensed condition comprises a time.

20. The method of claim 17 wherein the generating a transaction barcode at the mobile telephone, the transaction barcode including an account identifier and the sensed condition further comprises using a unique sensed condition as an encryption key to encrypt the transaction barcode.