A digital signal receiving and recording system including a digital broadcaster receiver and a digital signal recorder, the system comprising: a first input circuit comprised in said digital signal recorder for inputting an analog signal; a converter comprised in said digital signal recorder which converts said analog signal into a first digital signal; a key information generating circuit (711, 713) comprised in said digital signal recorder which generates at least one first key information; a key generating circuit comprised in said digital signal recorder which is supplied with said first key information and performs a predetermined calculation and generates a first key; a first encryption circuit comprised in said digital signal recorder which is supplied with said first key and said first digital signal and encrypts said first digital signal in blocks configured with a plurality of bits and outputs the encrypted first digital signal with said first key; a second encryption circuit comprised in said digital broadcast receiver for encrypting a second digital signal based on a second key information with the same encryption method as said first encryption circuit, the second encryption circuit being capable of switching between either a function of encrypting said second digital signal based on said second key information and a function of passing said second digital signal without encryption according to whether duplication of said second digital signal is permitted; a second input circuit comprised in said digital signal recorder for inputting the encrypted or unencrypted second digital signal and said second key information from the second encryption circuit; and a recording circuit comprised in said digital signal recorder which selects and records said first key information with said encrypted first digital signal or said second key information with said encrypted or unencrypted second digital signal in a predetermined area of said recording medium. a first input circuit comprised in said digital signal recorder for inputting an analog signal; a converter comprised in said digital signal recorder which converts said analog signal into a first digital signal; a key information generating circuit (711, 713) comprised in said digital signal recorder which generates at least one first key information; a key generating circuit comprised in said digital signal recorder which is supplied with said first key information and performs a predetermined calculation and generates a first key; a first encryption circuit comprised in said digital signal recorder which is supplied with said first key and said first digital signal and encrypts said first digital signal in blocks configured with a plurality of bits and outputs the encrypted first digital signal with said first key; a second encryption circuit comprised in said digital broadcast receiver for encrypting a second digital signal based on a second key information with the same encryption method as said first encryption circuit, the second encryption circuit being capable of switching between either a function of encrypting said second digital signal based on said second key information and a function of passing said second digital signal without encryption according to whether duplication of said second digital signal is permitted; a second input circuit comprised in said digital signal recorder for inputting the encrypted or unencrypted second digital signal and said second key information from the second encryption circuit; and a recording circuit comprised in said digital signal recorder which selects and records said first key information with said encrypted first digital signal or said second key information with said encrypted or unencrypted second digital signal in a predetermined area of said recording medium.