The invention relates to telecommunications, in particular to methods and means for transmitting digital messages and can be used for transmitting information through wire channels and telecommunication channels using electromagnetic waves. The use of said channels is simplified by excluding multiplication and division operators from the coding and a decoding process. Said invention makes it possible to transmit any messages from elements of Abelian group including code words whose elements are matrixes, polynomials, numbers of mixed-base notation and nonpositional notation. The inventive encoder comprises a driver clock (7), a function g<2> calculator (8), a pulse generator (9) having recurrent frequency of f(k+1) / k, a pulse recurrent frequency doubler (10), a ring counter (11) up to k, an adder-accumulator of elements of Abelian group (12), a key (13), a ring counter (14) up to (2k+1), an AND component (15), a main memory unit (16), a key (17), a trigger (18), a main memory unit (19) and a ring counter (20) up to (k+1). The inventive decoder comprises a driver clock (21), an adder-accumulator of elements of Abelin groupoid (21), a pulse generator (23) having recurrent frequency of fk(k+1) / k, a pulse recurrent frequency doubler (24), a ring counter (25) up to (k+1), a key (26), a main memory unit (27), a key (28), an AND component (29), a ring counter up to [2(k+1)+1] (30), an identification unit provided with a single element of Abelian group (31), a trigger (32), a main memory unit (33) a key (34), a ring counter (35) up to k.