An RMTL gate includes at least two logic blocks, where at least one of the logic blocks operates in multiple modes. The respective logic block mode(s) are selected by a topology selector which applies mode control signals to the logic blocks in order to obtain a selected topology for logic circuit operation. RMTL logic gates may be cascaded and/or interconnected to form an RMTL logic circuit with multiple logic gates which may operate with dynamically varying topologies. Use of random, semi-random or specified control sequences may protect the logic circuit against security attacks.