Patent ID: 7545928
Filing Date: 2009-06-09
Classification: H04L

Abstract:
1. An improved security processing circuit for performing 3DES IPsec security processing services for a host system using a DES engine, the security processing circuit comprising: the DES engine having a message input, a cipher key input, and a pre-data output, the engine adapted to receive and selectively process a block of data from the message input of the security processing circuit during a first DES processing operation, and subsequently to process data from an intermediate result during second and third DES processing operations and store an intermediate result of the third DES processing operation to the pre-data output; a security keys circuit having a set of cipher keys input and a key output, the security keys circuit operable to select and transfer a different cipher key to the key output coupled to the cipher key input of the DES engine selected from the set of cipher keys associated with each DES processing operation during the first, second and third DES processing operations; and a data output circuit having a pre-data input and a data output, the pre-data input of the data output circuit coupled to the pre-data output of the DES engine, and the data output selectively coupleable to the host system, the data output circuit operable to further security process data from the pre-data input and to selectively exclusive OR an initialization vector with the processed data and latch a final third DES result to the data output of the security processing circuit for use by the host system, wherein the DES engine comprises: