摘要:
A novel mechanism efficiently synchronizes the contents of databases stored on nodes of a computer network to-ensure that those contents are consistent. The mechanism comprises a database identifier generated by a node of the computer network and distributed to other receiving nodes coupled to the network. The database identifier is uniquely representative of the contents of the distributing node's database and the receiving nodes compare this unique identifier with their own generated database identifiers to determine if the identifiers, and thus their databases, are consistent and synchronized.
摘要:
A novel synchronization mechanism synchronizes delivery of data packets over on-demand links of a computer network in a manner that efficiently utilizes those links. The mechanism comprises control information generated by a source node and stored in a network layer header of a data packet transmitted to a destination node via at least one router coupled to an on-demand link of the network. Depending upon the state of the control information the router is instructed whether to immediately dial the link to establish a connection for delivery of the packet to the destination node.
摘要:
A technique for generating, distributing and maintaining a list of operational nodes in a network using a nonbroadcast communication medium, wherein the nodes first collectively agree on the identity of a designated node. Once the designated node is agreed on, the other nodes periodically send Hello messages to it and the designated nodes compiles a list of operational nodes based in part on the Hello messages it receives, and periodically sends a Hello message to each node on the list. The Hello message from the designated node includes a list of addresses of active neighbor nodes, so that every node periodically receives a list of operational neighbor nodes. The number of messages needed to implement this scheme is proportional to the number of nodes, rather than the square of the number of nodes as in a conventional approach in which each node advised every other node of its presence. Selection of the designated node can be on the basis of some unique property of each node, such as identification number or an encoded priority.
摘要:
An encryption system employing a one-time key-pad uses a shared secret number and a one-way hash function with which both the originator and recipient of a message generate successive segments of a key-pad to encrypt and decrypt the message respectively. In one arrangement each key-pad segment is generated by applying the hash function to a combination of the secret number and the previous key-pad segment. In the other embodiment of the invention, each key-pad section is generated by applying the one-way hash function to a combination of the secret number and a corresponding segment of the ciphertext version of the message.
摘要:
A signature system, such as an El Gamal or DSS system, involving the use of a long-term secret number and a per-message secret number generates the per-message secret number without the use of a random number generator or non-volatile storage. The per-message secret number is generated by applying a one-way hash function to a combination of the long-term secret number and the message itself.
摘要:
A novel switch architecture maintains the sequence of packet cells, received at one port of a multicast port group, during subsequent transfer of the cells to the remaining ports of the group. The novel architecture includes a 2-stage buffering arrangement whereby the first stage comprises a plurality of local buffers, each associated with a port of the switch, and the second stage comprises a single, global buffer. Each local buffer services its associated port of the multicast port group by temporarily storing incoming packet cells until a complete packet is received at that port, at which time the packet cells may be passed to the global buffer as outgoing cells. The global buffer services the remaining ports of the multicast port group by forwarding copies of the outgoing cells, in sequence, to those ports.
摘要:
A device and related method for coupling segments of an extended local area network (LAN) in such a way that message traffic employing inter-network protocols such as TCP/IP will be handled without the difficulties usually associated with bridges, and without the complexity and expense of full IP router capability. The device operates like a bridge for non-TCP/IP traffic. For TCP/IP traffic it operates in a bridge-like manner but maintains a database associating extended LAN segment addresses with port numbers in the device, so that packets can be automatically forwarded over a spanning tree connecting the network segments. A host computer in any network segment can address others in different network segments of the extended LAN as though all were in a single LAN. The device of the invention functions to block the flow of ARP messages and to generate ARP replies that render the device of the invention transparent to hosts within the extended LAN. The device is also transparent to true IP routers, which may still be used to effect communication with points outside the extended LAN.
摘要:
Stored information used for routing packets of a network of nodes interconnected by links. A link state packet is sent to the first node indicating the states of links connected to some given node in the network. At the first node, an attempt is made to derive from the link state packet sent in step (a), the states of the links. If the states of fewer than all of the links connected to the given node are derived in step (b), the stored information used for routing packets is updated using the derived link states without regard to other link state packets sent to the first node. Another aspect features organizing, at a node in a network of nodes interconnected by links, a database of entries concerning respective links, by (a) providing indicators associated with the entries, (b) when a link becomes inoperable, setting or clearing the indicator associated with the entry related to the link, and (c) when the link becomes operable, clearing or setting the indicator. Another aspect features organizing information concerning the states of links interconnecting nodes of a network of nodes, the information being grouped in link state packets indicating the states of links connected to respective source nodes. The link state packets are ordered, a range of the link state packets in the order is selected, and a summary is formed including information indicating the boundaries of the selected range, and information identifying each link state packet in the selected range.
摘要:
Some embodiments provide a system to generate a key pair. During operation, the system can receive a request to generate the key pair, wherein the key pair is generated by a key assigner, and wherein the key pair is associated with a user. Next, the system can determine a secret associated with the key assigner. Specifically, the system can determine the secret by determining an initial secret associated with the key assigner, and by applying a one-way hash function to the initial secret one or more times. The system can then determine a seed based on the secret. Specifically, the system can determine the seed by cryptographically combining the secret with information associated with the user. Next, the system can generate the key pair by using the seed as an input to a key generator. The system can then return the key pair to a requestor.
摘要:
One embodiment of the present invention provides a system that manages secret keys for messages. During operation, the system receives a desired expiration time T from an encrypter, and possibly a nonce N, at a server that manages keys. If N is not sent by the encrypter, it is generated by a key managing server. Next, the system chooses a secret ST, with an expiration time close to T, and an identifier IDS from a database for which secret ST can be retrieved using the identifier IDS. If such an ST is not already in the database, the server generates a new ST and IDS. The system then calculates a hash H=h(N,ST), and sends H and IDS from the server to the encrypter. The encrypter then encrypts M with H to form {M}H, and communicates ({M}H, N, IDS) to a message reader. The message reader then sends N and IDS to the server. The server then uses IDS to lookup ST, recalculates H=h(N,ST), and sends H to the message reader, thereby enabling the message reader to decrypt {M}H to obtain M. Note that by using the secret ST associated with the expiration time T and the nonce N, the server is able to reconstruct the secret key H for the message M without having to maintain per-message state information.