Browse Prior Art Database

Method for enforcing update of software

IP.com Disclosure Number: IPCOM000015862D
Original Publication Date: 2002-Jul-20
Included in the Prior Art Database: 2003-Jun-21
Document File: 2 page(s) / 82K

Publishing Venue

IBM

Abstract

Disclosed is the method for a software provider to ensure that all users are running the latest version, while allowing them to avoid sending any information when they purchase or upgrade the software. This method is also applicable to the software running in the environment disconnected from a network.

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Method for enforcing update of software

   Disclosed is the method for a software provider to ensure that all users are running the latest version, while allowing them to avoid sending any information when they purchase or upgrade the software. This method is also applicable to the software running in the environment disconnected from a network.

Primitive token

Function for verifying token

S0 S1 St

f f f

Initial token

software

St

Software Provider

User

New token

Before token renewal After token renewal

Fig. 1 Initial settings (top) and token renewal procedure (bottom)

The top figure of Fig. 1 describes the initial settings. First, the software provider prepares a primitive token S_0 and a function f for verifying token. The function f is a one-way function. The provider then generates an initial token S_t by applying the function to the primitive token for t times. Upon the shipment of the software, the initial token and the function are embedded into it. The initial token and the function are common in all copies of the software. The software also has a predetermined expiration date and it does not allow its users to use after the period, unless a new token is supplied.

The new token is generated by the provider, by applying the function to the primitive token for (n-1) times, when S_n is the latest token that had been already distributed. The software verifies the new token S_(n-1) by making sure that the result of applying the function f to the new token is same as the old token in the software. If the token is valid, the expiration date is extended for a certain period, and the t...