We present a novel generic construction of an insider secure signcryption scheme with non-interactive non-repudiation. Our generic construction uses as building blocks a signature scheme, a key encapsulation mechanism (KEM), a keyed hash function, a symmetric encryption scheme, and a pseudo--random function. We show that our construction is insider secure in the dynamic multi--user model, without resorting the random oracle or the key registration model; it provides non--interactive non repudiation.