US 12,010,243 B2 · Methods and devices for providing message authentication code suitable for short messages

Abstract

This application relates to devices and methods of authenticating messages exchanged over a network between a transmitter and a receiver. The transmitter generates a truncated MAC code by selecting predetermined bits from a message authentication code (MAC) computed over a concatenation of a part of the message with a part of a previously transmitted message. The transmitter appends the truncated MAC code to the message for transmission. The receiver receives a previously transmitted message, the currently transmitted message, and the truncated MAC code, and generates an expected truncated MAC code by selecting predetermined bits from a message authentication code (MAC) computed over a concatenation of the part of the message with the previously transmitted message. The receiver authenticates the message and the previously transmitted message if the truncated MAC code as received is identical to the expected truncated MAC code.

Claims14

Dependent claims

A method of authenticating messages exchanged over a network between a transmitter and a receiver, the method comprising:

transmitting a message at a transmitter side;
generating a truncated message authentication code (MAC) by selecting or generating predetermined bits from a MAC computed over a concatenation of a predetermined part of the message with at least one predetermined part of a previously transmitted message;
wherein a bitlength of truncated MAC is smaller than a bitlength of the message authentication code;
appending the truncated MAC to the message for transmission;
authenticating a message at a receiver side;
receiving a previously transmitted message, the message and the truncated MAC code;
generating an expected truncated MAC by selecting or generating predetermined bits from a MAC computed over a concatenation of a predetermined part of the message with at least one predetermined part of a previously transmitted message, and
authenticating the message and the previously transmitted message if the truncated MAC as received is identical to the expected truncated MAC, and
not authenticating the message and the previously transmitted message if the truncated MAC as received is not identical to the expected truncated MAC, overriding an authentication of the previously transmitted message.

6 more elements

A method of authenticating messages received by a receiver over a network, the messages comprising a truncated message authentication code (MAC) computed by selecting or generating predetermined bits from a MAC computed over a concatenation of a predetermined part of the message with at least one predetermined part of a previously transmitted message, wherein a bitlength of truncated MAC is smaller than a bitlength of the MAC, the method comprising:

receiving a previously transmitted message, the message, and the truncated MAC,
generating an expected truncated MAC by selecting or generating predetermined bits from a MAC computed over a concatenation of a predetermined part of the message with at least one predetermined part of a previously transmitted message;
authenticating the message and the previously transmitted message if the truncated MAC as received is identical to the expected truncated MAC;
and
not authenticating the message and the previously transmitted message if the truncated MAC as received is not identical to the expected truncated MAC, overriding an authentication of the previously transmitted message.

2 more elements

Dependencies are inferred from the claim text.

Methods and devices for providing message authentication code suitable for short messages

Life of this patent

Methods and devices for providing message authentication code suitable for short messages

Life of this patent

Abstract

Claims14