SECURELY USING A DISPLAY TO EXCHANGE INFORMATION
A first device has a display that is able to show information. The information is to be exchanged with a second device. The information is cleared from the display following receipt of an indication from the second device that the information has been successfully inputted at the second device.
1 . A method for generating a symmetric key, the method comprising:
generating a first random number at a first device;
generating a first public key based on the first random number;
generating a second random number at the second device; and
generating a second public key based on the second random number.
2 . The method of claim 1 wherein the first device sends the first public key to the second device.
3 . The method of claim 1 wherein the second device sends the second public key to the first device.
4 . The method of claim 1 wherein the first device and second device are one of a mobile device and a smart card reader.
5 . The method of claim 2 wherein the first device generates a symmetric key based on the first public key and the second public key.
6 . The method of claim 3 wherein the second device generates a symmetric key based on the first public key and the second public key.
7 . The method of claim 5 wherein the generation of the symmetric key at the first device occurs before, after or concurrently with the generation of the symmetric key at the second device.
8 . The method of claim 1 wherein the first and second public keys are calculated based on the formula:
p=f ( S ) R A mod p
9 . The method of claim 5 wherein the symmetric key is calculated based on the formula:
K=p R A mod p