Method and apparatus for secure identification of a mobile user in a communication network

A communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain, associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said communication system comprising:

• means for deriving said synchronization indication from numbers located in said home domain, and available to said foreign domain;
• means for encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• means for providing an identifier of said home domain to said foreign domain;
• means for transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• means for determining, within said home domain, an identity of said mobile user, utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting means.

A method, within a communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said method comprising the steps of:

• encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• providing an identifier of said home domain to said foreign domain;
• transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• determining, within said home domain, an identity of said mobile user utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting step, wherein said encryption function is a one-way function, and said identifier is a secondary identifier of said mobile user, said encrypting step comprising the step of encrypting said identifier, said synchronization indication, and said password such that decryption of said encrypted message is only possible within said home domain.

A method, within a communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said method comprising the steps of:

• pre-computing, within said home domain, prior to a synchronization interval indication, one or more potential encrypted messages for use in a future time interval;
• storing said pre-computed potential encrypted messages in a translation table;
• encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• providing an identifier of said home domain to said foreign domain;
• transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• determining, within said home domain, an identity of said mobile user utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting step.

A method, within a communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said method comprising the steps of:

• establishing for said home domain, a domain-wide time interval;
• encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• providing an identifier of said home domain to said foreign domain;
• transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• determining, within said home domain, an identity of said mobile user utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting step.

A communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain, associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said communication system comprising:

• means for encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• means for providing an identifier of said home domain to said foreign domain;
• means for transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• means for determining, within said home domain, an identity of said mobile user, utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting means, wherein said encryption function is a one-way function, and said identifier is a secondary identifier of said mobile user, said means for encrypting comprising means for encrypting said identifier, said synchronization indication, and said password such that decryption of said encrypted message is only possible within said home domain.

A communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain, associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said communication system comprising:

• means for pre-computing, within said home domain, prior to a synchronization interval indication, one or more potential encrypted messages for use in a future time interval;
• means for storing said pre-computed potential encrypted messages in a translation table;
• means for encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• means for providing an identifier of said home domain to said foreign domain;
• means for transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• means for determining, within said home domain, an identity of said mobile user, utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting means.

A communication system, for securely identifying a mobile user, said communication system including a plurality of users, a home domain, associated with said mobile user, a foreign domain, and a synchronization indication, said synchronization indication utilizing a time interval indication to synchronize said mobile user's input within said foreign domain with said home domain, said mobile user having an identifier and a password, said communication system comprising:

• means for establishing for said home domain, a domain-wide time interval;
• means for encrypting said identifier, said synchronization indication, and said password utilizing an encryption function;
• means for providing an identifier of said home domain to said foreign domain;
• means for transmitting an encrypted message including said encrypted identifier, said encrypted synchronization indication, and said encrypted password to said home domain;
• and
• means for determining, within said home domain, an identity of said mobile user, utilizing said encrypted message, said encryption function, and said synchronization indication in response to said transmitting means.