Thepaperproposesanovelalgorithmtogettheencryptionmatrix.Firstly,achaoticsequencegeneratedbyChebyshevchaoticneuralnetworksisconvertedintoaseriesoflow-orderintegermatricesfromwhichavailableencryptionmatricesareselected.Then,ahigherorderencryptionmatrixrelatingrealworldapplicationisconstructedbymeansoftensorproductionmethodbasedonselectedencryptionmatrices.Theresultsshowthattheproposedalgorithmcanproducea'one-timepadcipher'encryptionmatrixwithhighsecurity;andtheencryptionresultshavegoodchaosandauto-correlationwiththenaturalfrequencyoftheplaintextbeinghiddenandhomogenized.