A method for decorrelating input signals from a physical identifier, in a system having one or more processors, comprising: - providing input signals from a physical identifier; - providing a decorrelation matrix; - generating output signals, comprising decorrelating the input signals by applying the decorrelation matrix to the input signals; and - providing the output signals at an output; wherein the providing of the decorrelation matrix comprises - providing an initial matrix, the initial matrix being an orthogonal matrix; and - determining the decorrelation matrix from the initial matrix by, comprising - at least once selecting and applying at least one of a plurality of matrix extensions on the initial matrix, wherein each of the plurality of matrix extensions generates, from an input orthogonal matrix, a further orthogonal matrix with higher matrix dimension than the input orthogonal matrix; - wherein the at least once selecting at least one of a plurality of matrix extensions comprises selecting adaptively at least one of the plurality of matrix extensions dependent on the input signals from the physical identifier and wherein at least one of a plurality of matrix extensions is selected which causes a smallest value of average bit error probabilities in the generated output, wherein the physical identifier is a physical unclonable function. - providing input signals from a physical identifier; - providing a decorrelation matrix; - generating output signals, comprising decorrelating the input signals by applying the decorrelation matrix to the input signals; and - providing the output signals at an output; - providing an initial matrix, the initial matrix being an orthogonal matrix; and - determining the decorrelation matrix from the initial matrix by, comprising - at least once selecting and applying at least one of a plurality of matrix extensions on the initial matrix, wherein each of the plurality of matrix extensions generates, from an input orthogonal matrix, a further orthogonal matrix with higher matrix dimension than the input orthogonal matrix; - wherein the at least once selecting at least one of a plurality of matrix extensions comprises selecting adaptively at least one of the plurality of matrix extensions dependent on the input signals from the physical identifier and wherein at least one of a plurality of matrix extensions is selected which causes a smallest value of average bit error probabilities in the generated output, wherein the physical identifier is a physical unclonable function. - at least once selecting and applying at least one of a plurality of matrix extensions on the initial matrix, wherein each of the plurality of matrix extensions generates, from an input orthogonal matrix, a further orthogonal matrix with higher matrix dimension than the input orthogonal matrix; - wherein the at least once selecting at least one of a plurality of matrix extensions comprises selecting adaptively at least one of the plurality of matrix extensions dependent on the input signals from the physical identifier and wherein at least one of a plurality of matrix extensions is selected which causes a smallest value of average bit error probabilities in the generated output, wherein the physical identifier is a physical unclonable function.