An oscillator circuit including an integrated circuit amplifier, an integrated circuit active resistance circuit to set the gain of the amplifier, a crystal resonator to set the frequency of the signal generated by the oscillator circuit, and a pair of capacitors respectively situated at the inputs and outputs of the amplifier to assist in the starting of the oscillation signal. Each of the challenge-reply sets includes at least a challenge-reply pair for use in off-line authentication of the user for a particular resource available through the recipient unit. The waste developing agent outlet is closed by a second shutter member when the opening is opened.