Telcordia Technologies

About: Telcordia Technologies is a based out in . It is known for research contribution in the topics: Network packet & Node (networking). The organization has 3097 authors who have published 4737 publications receiving 237882 citations.

Apparatus and method for large scale ATM switching

Abstract: Apparatus and method for large scale asynchronous transfer mode (ATM) switching utilizing tunable lasers and fixed-tuned receivers are provided. The apparatus, an optical switch, includes a plurality of input modules for receiving ATM cells to be switched and a plurality of output modules for outputting the switched ATM cells. The optical switch also includes an optical transmission network for optically transmitting each ATM cell from an input module to a particular output module, and a contention resolution device in electrical communication with the plurality of input modules for selecting the ATM cells from the plurality of input modules to be switched. Preferably, each output module includes a plurality of fixed-tuned receivers and each input module includes a plurality of tunable lasers. The fixed-tuned receivers of each output module are tuned to a particular wavelength so as to pass only those ATM cells optically received from the optical transmission network at the particular wavelength. The tunable lasers are tunable to a plurality of distinct wavelengths for optically transmitting the ATM cell to the optical transmission network at the particular distinct wavelength associated with the output module to which the ATM cell is destined.

Passive photonic loop architecture employing wavelength multiplexing

Abstract: A fiber optic subscriber loop architecture is disclosed. The architecture utilizes a double star configuration comprising a Central Office and a plurality of Remote Nodes. Illustratively, in the Central Office, one bank of N lasers supplies wavelengths λ1, λ2 . . . λN in a first wavelength band to form channels on which downstream information will be transmitted to subscribers. In one embodiment, a second bank of N lasers operating at wavelengths λN+1, λN+2 . . . λ2N in a second wavelength band is used to form unmodulated channels to be delivered to subscribers for use in subsequent upstream transmissions. Groups of N wavelength channels are combined via WDM techniques at the Central Office before being transmitted over feeder fibers to the Remote Nodes. In the downstream direction, the Remote Nodes rearrange the wavelength channels received from the Central Office so as to route two wavelength channels, one modulated channel from the first wavelength band and one unmodulated channel from the second wavelength band, to each of a plurality of subscriber premises attached thereto. At each subscriber station, the modulated channel is decoded while the unmodulated channel is modulated with upstream information and transmitted back to the associated Remote Node. Each Remote Node multiplexes groups of the modulated channels from the second wavelength band and routes them back to the Central Office over the feeder fibers. In the above-described double-star subscriber loop architecture, there are no active devices in the Remote Nodes.

Public key authentication and key agreement for low-cost terminals

Abstract: A method for achieving mutual authentication and session key agreement between a first party 12 which has minimal computational resources and a second party 18 which has substantial computational resources utilizes a modular square root operation for certificate authentication and key distribution and an ElGamal, NIST DSS, or other efficient signature operation for obtaining the signature of a message. Theses operations are highly advantageous in a system with asymmetric resources because the computation power required to perform these operations is far less than the computation power required to invert these operations. The entire mutual authentication and session key agreement method can be carried out using only between one and three modular multiplications on the weak computational side.

Cryptographic Counters and Applications to Electronic Voting

Abstract: We formalize the notion of a cryptographic counter, which allows a group of participants to increment and decrement a cryptographic representation of a (hidden) numerical value privately and robustly. The value of the counter can only be determined by a trusted authority (or group of authorities, which may include participants themselves), and participants cannot determine any information about the increment/decrement operations performed by other parties. Previous efficient implementations of such counters have relied on fully-homomorphic encryption schemes; this is a relatively strong requirement which not all encryption schemes satisfy. We provide an alternate approach, starting with any encryption scheme homomorphic over the additive group Z2 (i.e., 1-bit xor). As our main result, we show a general and efficient reduction from any such encryption scheme to a general cryptographic counter. Our main reduction does not use additional assumptions, is efficient, and gives a novel implementation of a general counter. The result can also be viewed as an efficient construction of a general n-bit cryptographic counter from any 1-bit counter which has the additional property that counters can be added securely. As an example of the applicability of our construction, we present a cryptographic counter based on the quadratic residuosity assumption and use it to construct an efficient voting scheme which satisfies universal verifiability, privacy, and robustness.

Self-healing meshed network using logical ring structures

Abstract: Logical hybrid ring arrangements are disclosed which can withstand a cut communication path or a failed node. A logical ring is formed by a cascade of (i) physical hybrid ring segments, each composed of a pair of unidirectional communication paths propagating multiplexed subchannels and interposed add-drop multiplexer nodes, and (ii) cross-connect nodes terminating the segments. Each cross-connect node routes an incoming subchannel from one segment to an outgoing subchannel on another segment. Each segment may operate at a different multiplexed signal rate, so a logical ring can be composed of segments operating at different rates. Moreover, subchannels on an incoming segment may be allocated to a plurality of outgoing segments, thereby configuring multiple logical rings which may serve to balance communication traffic over the logical rings.