A method for securing a data carrier, based on placing, onto the surface of the data carrier, a final picture in the form of a matrix, the matrix consisting of at least two colored pixels arranged such that, when reading in the frequency space, a hidden picture (80, 80') is presented, the method including generating an initial picture (10, 10'), executing the Fourier transformation, generating a hidden picture, modification of the spatial frequencies of the initial picture (10, 10'), and executing the inverse Fourier transformation, wherein in the step of generating an initial picture (10, 10'), one defines the size of the initial picture in pixels, where, for every pixel, one pseudorandomly generates a value from a predefined range of natural numbers, where every natural number from the predefined range represents another pixel color, and the generated initial picture takes the form of an initial matrix (22, 24, 30, 40, 50, 60) in which every pixel has a particular color, in the step of generating a hidden picture (80, 80'), a hidden picture is defined in the form of the matrix of the hidden picture (80, 80'), that is to be hidden in the final picture, the generated initial picture (10, 10') is subjected to two-dimensional Fourier transformation generating a matrix of the spatial frequencies of the initial picture, every pixel of the matrix of the spatial frequencies of the initial picture is modified according to the pixel values of the hidden picture according to the matrix of the hidden picture so that when the hidden picture pixels are of a first color, one modifies no frequency space, and when the hidden picture pixels are of a second color, one brightens the pixels of the hidden picture, the picture (12, 12') of the spatial frequencies of the initial picture, modified by the hidden picture, is subjected to the inverse Fourier transformation generating a picture with the hidden picture, the generated picture with the hidden picture is subjected to thresholding, the obtained matrix with the hidden picture after the thresholding is used for generating the final picture, where every pixel of the matrix with the hidden picture is substituted by a sub-picture after the thresholding, where all the pixels of the same colors are substituted by the same sub-pictures, the final picture is applied to the data carrier. in the step of generating an initial picture (10, 10'), one defines the size of the initial picture in pixels, where, for every pixel, one pseudorandomly generates a value from a predefined range of natural numbers, where every natural number from the predefined range represents another pixel color, and the generated initial picture takes the form of an initial matrix (22, 24, 30, 40, 50, 60) in which every pixel has a particular color, in the step of generating a hidden picture (80, 80'), a hidden picture is defined in the form of the matrix of the hidden picture (80, 80'), that is to be hidden in the final picture, the generated initial picture (10, 10') is subjected to two-dimensional Fourier transformation generating a matrix of the spatial frequencies of the initial picture, every pixel of the matrix of the spatial frequencies of the initial picture is modified according to the pixel values of the hidden picture according to the matrix of the hidden picture so that when the hidden picture pixels are of a first color, one modifies no frequency space, and when the hidden picture pixels are of a second color, one brightens the pixels of the hidden picture, the picture (12, 12') of the spatial frequencies of the initial picture, modified by the hidden picture, is subjected to the inverse Fourier transformation generating a picture with the hidden picture, the generated picture with the hidden picture is subjected to thresholding, the obtained matrix with the hidden picture after the thresholding is used for generating the final picture, where every pixel of the matrix with the hidden picture is substituted by a sub-picture after the thresholding, where all the pixels of the same colors are substituted by the same sub-pictures, the final picture is applied to the data carrier.