Patent ID: 7376845
Filing Date: 2008-05-20
Classification: G06F,H04L

Abstract:
1. A method for calculating hashing of a message in a device communicating with a smart card, comprising: determining the message to hash, wherein the message is divided in data blocks, wherein message comprises a key and public data ordered in a sequence, and wherein the key is only known by the smart card; hashing, using a hash function, the key in the smart card to obtain a hashed key; hashing, using a hash function, at least a portion of the public data in the device to obtain hashed public data, wherein the hashed key and the hashed public data are used to obtain a hash of the message, wherein hashing the key comprises applying the hash function to the key when the key proceeds, based on the sequence, the public data in the message; wherein hashing the key comprises applying the hash function to the key and the hashed public data when the key follows, based on the sequence, the public data in the message; wherein hashing the public data comprises applying the hash function to the public data when the public data proceeds, based on the sequence, the key in the message; wherein hashing the public data comprises applying the hash function to the public data and the hashed key when the public data follows, based on the sequence, the key in the message.