Abstract: An event is registered in at least one node server in a directed data structure, which comprises a computationally linked series of nodes such that each node encodes information included in at least one preceding node. Within at least selected nodes of the directed data structure after at least one initial node, a representation of at least one history data structure is included and has a highest-level value computed based on inputs of lowest level input values, at least one said lowest level input value encoding node-specific information of at least one preceding node. In a verification phase, a purportedly valid lowest level input value is verified by recomputing the corresponding highest-level value from the representation of the history data structure included in the corresponding node.

Abstract: An event is registered in at least one node server in a directed data structure, which comprises a computationally linked series of nodes such that each node encodes information included in at least one preceding node. Within at least selected nodes of the directed data structure after at least one initial node, a representation of at least one history data structure is included and has a highest-level value computed based on inputs of lowest level input values, at least one said lowest level input value encoding node-specific information of at least one preceding node. In a verification phase, a purportedly valid lowest level input value is verified by recomputing the corresponding highest-level value from the representation of the history data structure included in the corresponding node.

Abstract: Blockchain blocks are provided with either or both of two element types that enable later verification of block validity. One element type is identifiers, such as signatures, of trusted validators that approve entry of the block into the blockchain. Another element is a history hash tree that encodes data from not only the current block, but also at least one previous block.

Abstract: Blockchain blocks are provided with either or both of two element types that enable later verification of block validity. One element type is identifiers, such as signatures, of trusted validators that approve entry of the block into the blockchain. Another element is a history hash tree that encodes data from not only the current block, but also at least one previous block.

Abstract: This invention concerns an enzymatic RNA molecule which is capable of specifically cleaving matrix metalloproteinase 13 (MMP-13) (also called collagenase-3) messenger RNA. The invention concerns further a pharmaceutical composition comprising the novel ribozyme and an expression vector encoding the same, and a composition comprising said vector. Furthermore, the invention concerns further a method for reducing or eliminating the expression of MMP-13 in vivo; a method for treating or preventing cancer, or preventing or inhibiting cancer growth, invasion or metastasis; and a method for treating or preventing various inflammatory conditions. The invention concerns also methods for detecting the level of MMP-13 in a tissue or body fluid, and the use of this information for the diagnosis of MMP-13 related diseases.