Abstract: A method for detecting an attack on a serial communications system which determines the status of messages transmitted via the serial communications system to obtain a sequence of statuses, compares the sequence of statuses with at least one reference sequence, and determines that there is an attack on the serial communications system in response to the sequence of statuses deviating from the reference sequence. The status of one of the messages is based on properties of the message and properties of a preceding message.

Abstract: Technologies and techniques for monitoring a communication bus. A number of electronic stations are networked by the communication bus. During operations, the messages transmitted via the communication bus are identified via an identifier, it being determined for each station which messages each station can send with which identifier. According to a uniqueness rule, it is prohibited for another station to send a payload message with an identifier that is already reserved for this station. In order to expose stations that introduce manipulated messages onto the communication bus, a protocol unit in a station maintains a list of the identifiers of the messages actually sent by the station. The attacker station can be identified via subsequent comparisons with this list.

Abstract: The present invention relates to a method for transmitting a message sequence via a data bus. The method comprises the transmission of an informational message containing an informational signal during an active phase, the transmission of a security message for initiating a rest phase and the transmission of rest messages containing a rest signal at the interval of a rest cycle time during the rest phase, wherein the informational signal and the rest signal differ from each other and wherein the security message and the rest messages differ from each other. Furthermore, the invention relates to a device for transmitting a message sequence via a data bus as well as a method and a device for detecting an attack on a message sequence transmitted via a data bus.

Abstract: A method for detecting an attack on a serial communications system which determines the status of messages transmitted via the serial communications system to obtain a sequence of statuses, compares the sequence of statuses with at least one reference sequence, and determines that there is an attack on the serial communications system in response to the sequence of statuses deviating from the reference sequence. The status of one of the messages is based on properties of the message and properties of a preceding message.

Abstract: The present invention relates to a method for transmitting a message sequence via a data bus. The method comprises the transmission of an informational message containing an informational signal during an active phase, the transmission of a security message for initiating a rest phase and the transmission of rest messages containing a rest signal at the interval of a rest cycle time during the rest phase, wherein the informational signal and the rest signal differ from each other and wherein the security message and the rest messages differ from each other. Furthermore, the invention relates to a device for transmitting a message sequence via a data bus as well as a method and a device for detecting an attack on a message sequence transmitted via a data bus.

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.