Abstract: A method and system for maintaining integrity and confidentiality of pages paged to an external storage unit from a physically secure environment. An outgoing page is selected to be exported from a physically secure environment to an insecure environment. An integrity check value is generated and stored for the outgoing page. In one embodiment, this takes the form of taking a one-way hash of the page using a well-known one-way hash function. The outgoing page is then encrypted using a cryptographically strong encryption algorithm. Among the algorithms that might be used in one embodiment of the invention are IDEA and DES. The encrypted outgoing page is then exported to the external storage. By virtue of the encryption and integrity check, the security of the data on the outgoing page is maintained in the insecure environment.

Abstract: Methods, apparatus and computer products provide solutions to the problem caused by the slow speed of public key signature algorithms. The solutions also solve problems of packet authentication for multicast and other scenarios requiring fast, compact digital signatures. Security guarantees required for packet authentication are provided in a way that can handle multiple independent flows, produces authentication fields of fixed size, works in the fully unreliable setting, does not require any packet delays and has the additional property of being able to withstand and smooth over irregular processor loading and bursty packet output rate. One aspect of the present invention uses a hybrid approach consisting of the signer creating a certificate for the public key of an efficient k-time signature scheme using a regular signature key. The signer then signing up to k messages with the private key corresponding to k-time public key.

Abstract: A system and method are provided for the distribution of digital licenses through a multi-level distribution chain using one or more clearinghouses. The system supports content providers, distributors, and end users. Content providers create and provide licenses. Distributors acquire licenses from content providers and upstream distributors, and can modify them in accordance with the terms of the original licenses. Distributors digitally sign modified licenses before providing to other users. Distributors optionally extend licenses to create new licenses and distribute them. End users acquire, download and activate licenses. Content providers and distributors can obtain tracking reports from clearinghouses detailing transactions (e.g., purchases, acquisitions, activations, and license compliance) associated with licenses as they progress down the distribution chain and are finally activated.

Abstract: Distributing information, including the steps of watermarking the digital content, distributing the digital content using a multi-source system, and partially fingerprinting digital content at each stage of moving information from a point of origin to the viewer. “Adaptation” of the digital content to the recipient includes maintaining the digital content in encrypted form at each such intermediate device, including decrypting the digital content with a key unique to both the device and the specific movie, selecting a portion of the watermark locations into which to embed information, embedding fingerprinting information into those locations sufficient to identify the recipient, and encrypting the fingerprinted digital content with a new such key.

Abstract: A method, apparatus and system to ensure the security in the information exchange and to provide list matching with higher efficiency and practicality. In a particular embodiment, each of lists to be subject to list matching is represented as a polynomial having roots equivalent to the items of the list. Then, polynomials generated for the lists to be subject to list matching are added according to a distributed secret computation. A list containing an item equivalent to a root of a polynomial resulting from the addition is created and output as the list of a common item.

Abstract: A method, system, computer program product, and method of doing business by digitally notarizing a collection of data streams, thereby improving security of the contents of the data streams. Preferably, public key cryptography is used, wherein the collection of data streams is digitally signed (i.e. notarized) using a private cryptographic key of a digital notary, such that an associated public cryptographic key can be used to verify the authenticity and integrity of the collection of data streams. One or more components which are involved in creating the data streams are preferably authenticated, and a unique identifier of each such component is included within cryptographically-protected information that is provided for the digital notarization. The authenticated identities of the components can therefore be determined from the digital notarization.

Abstract: In a computer network, documents are produced, the document is hashed to produce a fingerprint, and the fingerprint is encrypted to sign the document then the document signature is transmitted from the user system to a secure computer system. The secure computer system creates a time stamp including the document signature and a digital time. The secure system signs the time stamp to verify its origin. The time stamp and notary's signature are transmitted from the secure system to the user's system. The user has access to the notary's public key which is used for determining whether the time stamp is authentic. Then, if the document is revised, the revised document is hashed and the hash is combined with an indication that the revision is related to the original document. The indication could be a hash of the original document, the original document signature, the notary's time stamp for the original document, or the notary's signature for the original document.

Abstract: Disclosed is an electronic payment device and its method using an balanced binary tree for calculating a first data Xk of current consumption or a plurality of root values Rq from an initial value Xn of the amount of money that user purchases. The first data Xk is correspondent to a position value j with a respective relation of j=n−k+1. The first data Xk is generated according to the value of the binary code dm−1dm−2 . . . d1d0 of the position value j being a 0 or 1, by formula Xk=hd0(. . . (hdm−2(hdm−1(Xn)))). If the binary code di=0, i=m−1, m−2, . . . , 1, 0, then the first one-way function h0 is used as an operating function. Otherwise, the second one-way function h1 is operated when the binary code di=1. Moreover, a function operating device for an electronic payment using an balanced binary tree is also disclosed. The present invention requires less calculation than that in the prior art, and thus is more effective.

Abstract: In a tree-structural key distribution system, renewed data of a master key and medium key are sent along with a key renewal block (KRB). KRB is such that each of devices included as leaves of a tree structure has a leaf key and restricted node key. A specific KRB can be generated for a group identified by a specific node and distributed to the group to restrict a device for which the key can be renewed. Any device not belonging to the group cannot decrypt the key, whereby the security of key distribution can be assured. Especially in a system using a generation-managed master key, a master key renewed with KRB can be distributed.

Abstract: Techniques are disclosed for efficient computation of consecutive values of one-way chains and other one-way graphs in cryptographic applications. The one-way chain or graph may be a chain of length s having positions i=1, 2, . . . s each having a corresponding value vl associated therewith, wherein the value vi is given by vi=h (vl+1), for a given hash function or other one-way function h. An initial distribution of helper values may be stored for the one-way chain of length s, e.g., at positions given by i=2j for 0≦j≦log2 s. A given one of the output values vi at a current position in the one-way chain may be computed utilizing a first helper value previously stored for another position in the one-way chain between the current position and an endpoint of the chain. After computation of the given output value, the positions of the helper values are adjusted so as to facilitate computation of subsequent output values.

Abstract: A second digital credential that includes a first digital credential and a digital signature is received, and the validity of the second digital credential is determined. A determination is made whether the first digital credential is valid based on the validity of the second digital credential.

Abstract: The present invention relates in particular to a method for generating a digital signature (c, d) of a message M as well as a method for authenticating such a signature having the steps of defining a modulo N and a base g, a public key Y, and a private key x, these parameters N, g, Y, and x being linked by the relationship Y=gx (mod N), defining a hash function H the size of whose result has S bits, choosing a number r of T bits with T>=2S, calculating u from the following relationship u=gr*Yz where Z=2s, hashing the concatenation of M and u, by function H, the number thus obtained being the value c of the signature, and calculating the value d of the signature by the relationship: d=r+c*x.

Abstract: A combined digital signature is method of making a single public key digital signature on a number of messages, such that individual combined signatures may be extracted and individually presented. The mechanism of a combined digital signature is a combination of a hash tree whose leaves correspond to messages, together with a cryptographic signature made on the root of that hash tree. The invention comprises a method of making a combined signature, a method of extracting individual combined signatures, a method of verifying individual combined signatures, and the data format of an individual combined signature. The invention can increase performance of signature-making by a factor of several hundred over previous art.

Abstract: Generalized, low-cost, and easy digital signature verification techniques for use in information processing operations that require a plurality of digital signatures and series of information processing operations that require a plurality of digital signatures based on the progression of operations. Techniques are provided for verifying signatures on an information processing request, received via a network from a processing application computer, to which multiple digital signatures are to be affixed.

Abstract: A security service for an electronic marketplace that permits members of the marketplace to use any signing service to attach electronic signatures to documents resident on the marketplace regardless of format differences between the member's internal computer system and the electronic marketplace.

Abstract: A system and method for authenticating an image of an object, include at least one identifier associated with the object, a receiver for interrogating the at least one identifier to produce identification information, a camera system for recording an image from the object including the at least one identifier, and a composite generator for encoding the identification information from the receiver along with the image acquired by the camera system, to produce composite data.

Abstract: A method and system for overcoming the problems associated with certificate revocation lists (CRL's), for example, in a public key infrastructure. The invention uses a tree-based scheme to replace the CRL.

Abstract: A memory containing an authenticated search tree that serves for authenticating membership or non membership of items in a set. The authenticated search tree including a search tree having nodes and leaves and being associated with a search scheme. The nodes including dynamic search values and the leaves including items of the set. The nodes are associated, each, with a cryptographic hash function value that is produced by applying a cryptographic hash function to the cryptographic hash values of the children nodes and to the dynamic search value of the node. The root node of the authenticated search tree is authenticated by a digital signature.

Abstract: A digital signature protocol generates a signature component using a hash of an encrypted message. The component and encrypted message form a signature pair that is forwarded to a recipient. The encryption message is used to retrieve the encryption key at the recipient and authenticate information in the message. The signature pair may be applied to a data carrier as a bar code for use in mail delivery services. By utilizing a hash of the message, a reduced message length is achieved as individual signatures are not required for each component of the message.

Abstract: Upon receiving a message {ID′i−1, X′i−1, m′i−1, Yi−1} from a signer (i−1), a signer i generates a random number ri, then calculates Xi=gri mod p using pieces of public information p, q and g, then sets X′i=(X′i−1, Xi), m′i=(m′i−1, mi), then calculates ei=fi(X′i, m′i), di=hi(X′i, m′i) with public one-way functions fi and hi, calculates yi=(yi−1+diri+eisi) mod q using a secret random number si, sets ID′i=(ID′i−1, IDi), and sends information {ID′i,X′i,m′i,y′i} to the next signer (i+1). A verifier calculates ei and di with the one-way functions fi and hi using X′L and m′L contained in received information {ID′L, X′L, m′L, yL}, and makes a check to see if gyL≡X1d1 ILe1 . . .