Providing an information encrypting transmission and reception method in which separate transmission and reception of electronic signature are not required so that a sender and a receiver does not have to disclose their key information to each other, and it is very difficult or substantially impossible for a third person to interpret the key information or the encrypted information while the information is 100% reproducible by the receiver. Providing a sender server computer 5 for transmitting and receiving data of a sender 5 and a receiver server computer 6 for transmitting and receiving data of a receiver 4 that are connected to the web network; firstly encrypting bit data FD of original information such as plaintext to be transmitted from the sender 3 to the receiver 4 by performing anexclusive OR operation in use of bit data of electronic key of the sender 3 and transmitting the firstly encrypted bit data CR1 attached with personal data of the receiver 4 to the sender server computer 5; by the sender server computer 5, receiving bit data CS of the electronic key of the receiver 4 by submitting personal data of the receiver 4 to the data center 2, secondly encrypting the firstly encrypted bit data CR1 by performing exclusive OR operation in use of received bit data CS of the electronic key of the receiver 4, and transmitting the secondly encrypted bit data CR2 attached with personal data of the sender 3 and the receiver 4 to the receiver server computer 6.