Information processing apparatus, an authentication apparatus, and an external apparatus

A method of acquiring certification information in an information processing apparatus having a hardware processor and memory, the information processing apparatus using functions of a plurality of external apparatuses using certificate information from an authentication apparatus for authenticating a user, the method comprising the steps of:

• receiving authentication information for causing the authentication apparatus to authenticate the user by using the hardware processor;
• acquiring a master ticket, the master ticket indicating that the user has been authenticated by transmitting the authentication information to the authentication apparatus, wherein the master ticket allows the user to access all the plurality of external apparatuses;
• acquiring an authentication ticket that allows the user to access a particular one of the plurality of external apparatuses based on the master ticket from the authentication apparatus, the authentication ticket having a period of validity;
• and
• permitting use of a function of the particular one of the plurality of external apparatuses based on the master ticket, even in case the period of validity of the authentication ticket is expired.

A computer readable recording medium that contains a computer program that causes an information processing apparatus having a hardware processor and memory, the information processing apparatus using functions of a plurality of external apparatuses using certification information issued by an authentication apparatus for authenticating a user to perform the steps of:

• receiving authentication information for causing the authentication apparatus to authenticate the user by the hardware processor;
• acquiring a master ticket, the master ticket indicating that the user has been authenticated by transmitting the authentication information to the authentication apparatus, wherein the master ticket allows the user to access all the plurality of external apparatuses;
• acquiring an authentication ticket that allows the user to access a particular one of the plurality of external apparatuses based on the master ticket from the authentication apparatus, the authentication ticket having a period of validity;
• and
• permitting use of the a function of the particular one of the plurality of external apparatuses based on the master ticket, even in case the period of validity of the authentication ticket is expired.