Abstract: A multicast message transmission device and a message receiving protocol device for guaranteeing a fair message delivery time for a multicast message. At the receiving protocol device, a release time of the received multicast message is set to a prescribed time specified to all receiving protocol devices of the same multicast group, and the received multicast message is stored until the release time, and then released to a corresponding upper level device. At the transmission device, each receiving protocol device is authenticated, and then the encrypted multicast messages are transmitted to the receiving protocol devices, while a prescribed decryption key corresponding to the encryption key of the encrypted multicast message is distributed the authenticated receiving protocol devices prior to transmissions of the multicast messages.

Abstract: To prevent unauthorized reception, storage, copying and reproduction of digital media objects it is defined in addition to a scrambled broadcast format a scrambled storage format which is different from the broadcast format. A user's terminal equipment cannot receive, store or reproduce protected objects without a key which is advantageously a bit sequence stored on a portable memory medium and which can be different according to the type of use it gives entitlement to. To prevent the storing and later reproduction as such of data in the broadcast format, a time stamp is included in the broadcast format representing the time of broadcasting. A playback device cannot reproduce a broadcast-format object if the reproduction time differs from the time stamp included in the broadcast format. The reproduction time is advantageously read from a real time clock of a portable memory medium.

Abstract: A method for establishing a secured communication channel between a client and a server is disclosed where a program and a set of encryption information for establishing the secured communication channel are delivered from the server to the client. The set of encryption information is compact and can be used to quickly and efficiently encipher and decipher data. In particular, the client requests a program from the server via a first secured communication channel that can be established by a web browser under the HTTPS (Hypertext Transfer Protocol with SSL) protocol. The server in response dynamically generates a set of encryption information and a token identifying this particular set of encryption information. This information is then sent with the requested program. While the program can be written in any language, the language of choice is a platform-independent language such as Java.

Abstract: A multi-step signing system and method uses multiple signing devices to affix a single signature which can be verified using a single public verification key. Each signing device posesses a share of the signature key and affixes a partial signature in response to authorization from a plurality of authorizing agents. In a serial embodiment, after a first partial signature has been affixed, a second signing device exponentiates the first partial signature. In a parallel embodiment, each signing device affixes a partial signature, and the plurality of partial signatures are multiplied together to form the final signature. Security of the system is enhanced by distributing capability to affix signatures among a plurality of signing devices and by distributing authority to affix a partial signature among a plurality of authorizing agents.

Abstract: A first trusted authority, such as an originating certification authority, that stores key history data, such as private decryption keys for one or more subscribers, includes a key history exportation engine operative to generate a security key history exportation packet. The security key history exportation packet contains at least encrypted security key history data uniquely associated with a subscriber. A second trusted authority, such as a destination certification authority, includes a security key history importation engine operative to decrypt the security key history exportation packet. The retrieved security key history data then is stored and made accessible through the second trust authority for later access by the subscriber. The second trusted authority serves as a new trust anchor instead of the first trust authority.

Abstract: A method, computer system, and program product provides for authentication of user messages using PKI technology in environments where limited capacity prevents direct PKI technology use, and strong security is provided using magnetic swipe cards or the like, and a pass phrase is used for enhanced security and to avoid the need for special purpose devices. The invention is advantageous where there are limitations on the space available for PKI credentials, such as in the userid and password fields of a remote access protocol. PKI techniques are used without transferring lengthy keys or certificates once an initial registration process is complete. A secret key is used. A digest is computed of the secret key, the user's certificate serial number, and a time stamp. The digest, together with the user's certificate serial number and the time stamp, forms a compact message that may be transmitted. Private keys and secret keys are not sent during authentication. Replay attacks are prevented.

Abstract: Apparatus and method for authenticating that a sender has sent certain information via a dispatcher to a recipient is disclosed. The method includes the steps of: (a) providing a set A comprising a plurality of information elements a1, . . . an, said information element a1 comprising the contents of said dispatched information, and said one or more information elements a2, . . .

Abstract: Threshold cryptography (secret sharing) is used for exchanging a secret between a server and a client over an unreliable network. Specifically, a secret is computationally divided into N shares using a threshold encryption scheme such that any M of the shares (M less than or equal to N) can be used to reconstruct the secret. The N shares are spread over a number of transmitted messages, with the assumption that some number of the messages including a total of at least M shares will be received by the client. Upon receiving at least M shares, the client uses the at least M shares to reconstruct the secret using the threshold encryption scheme.

Abstract: A system and method for certified transmission of an electronic document, as verified by the generation of a certification indicia. Three embodiments of the system and method are disclosed, providing for the certified transmission of a document through an independent certification device or for direct transmission from a sender to a recipient. Furthermore, the resulting certification indicia may be generated by an independent certification device or by a portable processor at the sender or receiver's location.

Abstract: In a public key cryptosystem employing the El-Gamal algorithm, secret fresh random numbers are generated at a server and private keys of users, as encrypted with a symmetric algorithm by using individual user identifying keys determined by hashing the users' respective passphrases or biometric information (fingerprint, voiceprint, retina scan, or face scan) are maintained in a store accessible to the server, and the fresh random numbers and encrypted private keys are transmitted to the user equipment when needed via a network which is not secure. In order to prevent an attacker from discovering the random numbers or employing formerly used random numbers in a block replay attack, an interchange in the nature of a challenge response protocol is employed which passes at least one secret fresh random number from the server to the user equipment while also authenticating the user to the server.

Abstract: A method for providing secure remote control commands in a distributing computer environment. In the preferred embodiment of the invention, a network administrator or network management software creates a shutdown record, including an index or time stamp, for powering down a specified network computer(s). Prior to broadcast over the network, a secure one-way hash function is performed on the shutdown record. The result of the one-way hash function is encrypted using the network administrator's private key, thereby generating a digital signature that can be verified by specially configured network nodes. The digital signature is appended to the original shutdown record prior to broadcast to the network. Upon receiving the broadcast message, the targeted network computer(s) validates the broadcast message by verifying the digital signature of the packet or frame. The validation process is performed by decrypting the hash value representation of the shutdown record using the network administrator's public key.

Abstract: A message guaranty system for having a reliable third party (evidence preparing server) prepare evidence information attesting to the transmission and reception of a message by a transmitting and a receiving terminal. When the transmitting terminal furnishes the target message with evidence information before transmitting them to the destination, the system attests to the transmission and reception of that message once they are completed. When a message is to be sent illustratively from a workstation (WS) 1 to a workstation (WS) 2, the third-party evidence preparing server on the network first prepares transmission evidence based on a request from the WS 1 and sends it to the WS 1. The WS 1 sends the message along with the evidence to the WS 2. The evidence preparing server then prepares reception evidence based on a request from an evidence verifying server (a third party) acting for the WS 2.

Abstract: A system includes an accounting register; structure for creating and attaching a digital signature to a message; a memory having stored therein a plurality of different indemnification provisions and a plurality of different service rates each associated with a corresponding one of the plurality of different indemnification provisions; apparatus for selecting and associating a specific one of the plurality of different indemnification provisions to the digital signature; and a device for adjusting the accounting register, wherein at times when the specific one of the plurality of different indemnification provisions has been selected and associated with the digital signature the adjusting device accounts for a one of the plurality of different service rates that corresponds to the specific one of the plurality of different indemnification provisions.

Abstract: A method for validating a message packet communicated from a source node to a destination node in a computer network is disclosed. The source node and destination node have access to a clock mechanism synchronized with a common time frame. The method comprises generating a first security key using a time reference obtained from the clock mechanism and a password known by the source node and destination node, communicating the first security key with a message packet from the source node to the destination node, and when the first security key and message packet are received by the destination node, generating a second security key using the password and the time reference and comparing the second security key with the first security key. The message packet is discarded if the second security key does not correspond with the first security key.