The Vatican's chief spokesman, Joaquin Navarro-Vals, said cardinal electors would be moving Sunday afternoon into the Domus Sancta Marthae, the residence where they'll be staying until the election of a new pope.
The cardinals will be cut off from the outside world and will not be allowed to communicate with anyone who has not taken an oath of secrecy.
Dr. Navarro-Vals confirmed that 115 cardinals from 52 countries and representing five continents will be taking part in the election of the new pope - the 265th of the Catholic Church.
The spokesman said the conclave will begin with a Mass celebrated by all the cardinals on Monday morning. In the afternoon a procession of the cardinals would go from the Hall of Benedictions in the Apostolic Palace and end in the Sistine Chapel.
In the Sistine Chapel, Dr. Navarro-Vals said, all the cardinal electors will swear the oath of secrecy. The cardinal dean will read the formula of the oath, after which each cardinal, stating his name and placing his hand on the Gospel, will pronounce the words: "I promise, pledge and swear."
Voting could begin Monday afternoon but that is to be decided by the cardinals that day. On the following days cardinals will cast their ballots four times a day and, at least initially, a two-thirds majority will be required for a pope to be elected.
The Vatican has assured the name of the Catholic Church's new pope will remain secret until the announcement is made.
The spokesman said specialized technicians of the Vatican's police are responsible for all security surrounding the conclave. He said all the necessary precautions have been taken to ensure there will be no information leaks.