Apparatus for providing cryptographic support in a network

An interface for coupling a host computer to a high-speed telecommunications network, comprising a reassembler for reassembling and decrypting data that has been encrypted in accordance with a pre-defined key and segmented into a plurality of asynchronous transfer mode (ATM) cells, each cell comprising a virtual channel identifier (VCI) and a cell body, said reassembler comprising:

• (a) a cell manager for separating each cell body from that cell body's corresponding VCI;
• (b) a linked list manager for storing linked list data indicative of addresses at which said cell bodies are to be stored;
• (c) a content addressable memory (CAM) for storing said VCIs and providing pointers into said linked list data;
• (d) a lookup controller for writing said VCIs to said CAM, said lookup controller being operatively coupled to said cell manager, linked list manager, and CAM;
• (e) a reassembly buffer for storing said cell bodies, said reassembly buffer being operatively coupled to said linked list manager;
• and
• (f) a decryption circuit, operatively coupled to said cell manager, said linked list manager, and said reassembly buffer, for decryption said data in accordance with said key;
• wherein said cell manager, linked list manager, CAM, lookup controller, reassembly buffer, and decryption circuit operate concurrently with one another.

A reassembler, for use in an interface between a host computer and a high-speed telecommunications network, for reassembling and decrypting data that has been encrypted in accordance with a pre-defined key and segmented into a plurality of cells each of which comprises at least a virtual channel identifier (VCI) and a cell body, comprising:

• (a) first means for separating each cell body from its corresponding VCI and determining respective linked list reference addresses for the VCIs;
• (b) a decryption circuit for receiving cell bodies from said first means and decrypting said cell bodies in accordance with said key;
• (c) a first data path coupling said first means to said decryption circuit;
• (d) a reassembly buffer for storing said cell bodies after said cell bodies have been decrypted;
• (e) a second data path coupling said decryption circuit to said reassembly buffer;
• and
• (f) linked list manager for receiving said key from said host device and providing said key to said decryption circuit in parallel with movement of said cell bodies from said first means to said decryption circuit, and for storing linked list data indicative of addresses at which the decrypted cell bodies are stored in said reassembly buffer.

A method of operating an interface between a host computer and a high-speed telecommunications network, for use in reassembling and decrypting data that has been encrypted in accordance with a pre-defined key and segmented into a plurality of cells each of which comprises at least a virtual channel identifier (VCI) and a cell body, comprising the steps of:

• (a) separating each cell body from its corresponding VCI and determining respective linked list reference addresses for the VCIs;
• (b) receiving said key from said host device;
• (c) providing said cell bodies and said key in parallel to said decryption circuit;
• (d) decrypting said cell bodies in accordance with said key;
• (e) storing the decrypted cell bodies in a buffer;
• and
• (f) storing linked list data indicative of addresses at which the decrypted cell bodies are stored in said reassembly buffer.