Abstract: Method for the encryption of data as well as a corresponding decryption method are set forth. In order to guarantee a secure transmission of data with relatively little effort, an encryption method is provided in which a key vector with a second length is generated from a secret key information vector with a short length and a public matrix with a size corresponding to the first length times a second length, which is greater than the first size, and in which an encryption vector is formed by means of a first encryption method from a data vector with a third length, which is less than or equal to the second length, and the key vector.

Abstract: Method for the encryption of data as well as a corresponding decryption method are set forth. In order to guarantee a secure transmission of data with relatively little effort, an encryption method is provided in which a key vector with a second length is generated from a secret key information vector with a short length and a public matrix with a size corresponding to the first length times a second length, which is greater than the first size, and in which an encryption vector is formed by means of a first encryption method from a data vector with a third length, which is less than or equal to the second length, and the key vector.

Abstract: The invention relates to a method for carrying out a multiplication modulo M of two n-digit digital numbers (X, Y) in relation to a radix m by means of an integrated circuit. The inventive method consists of the following steps: conventionally determined partial products I=X<SB>1</SB>*Y(0=1=n?1), beginning with the highest-ranking place, are formed; the partial product (I) is added (4) to a subtotal multiplied by m, in order to form a new subtotal; the summands (S, C) of the new subtotal are added (5) to a value from a plurality of pre-calculated values (A) which are attributed to classes, in order to form a new subtotal; the new subtotal is used for the addition (4) of the next step (I?1); the new subtotal is approximately compared with the pre-determined classes in order to establish in which class the new subtotal falls; and the pre-calculated value (A) pertaining to the determined class is used as a summand for the corresponding addition (5) of the next step (i?1).

Abstract: Method for the encryption of data as well as a corresponding decryption method are set forth. In order to guarantee a secure transmission of data with relatively little effort, an encryption method is provided in which a key vector with a second length is generated from a secret key information vector with a short length and a public matrix with a size corresponding to the first length times a second length, which is greater than the first size, and in which an encryption vector is formed by means of a first encryption method from a data vector with a third length, which is less than or equal to the second length, and the key vector.