Abstract: In an example, a computing device is described. The computing device comprises an interface to receive a request from a signer for a state. The state is to be used as an input to generate a key under a stateful signature scheme. The computing device further comprises a processor. The processor is to identify an available state that the signer is authorized to use in response to the request received via the interface. The available state is identified from a set of states that can be used by the signer to maintain statefulness of the stateful signature scheme. The processor is further to instruct a reply to be sent to the signer via the interface. The reply comprises an indication of the state that the signer is authorized to use.

Abstract: According to examples, an apparatus includes a processor that is to receive a transaction for a smart contract on a blockchain to progress a state of a workflow instance of the smart contract. The processor is to identify a rule correlated to the received transaction among a set of rules for the smart contract and is to load the identified rule correlated to the received transaction into the smart contract. The processor is to determine whether the received transaction is valid based on application of the identified rule in the smart contract. Based on a determination that the received transaction is valid based on application of the identified rule, the processor is to progress the state of the workflow instance of the smart contract.

Abstract: Examples associated with ransomware attack monitoring are described herein. One example includes a monitor module to monitor files stored on the system for sequences of file accesses that match a predefined pattern of file accesses. An investigation module is activated based on a sequence of file accesses that match the predefined pattern. The investigation module logs actions taken by processes to modify files. A reaction module pauses a set of processes operating on the system based on the logging performed by the investigation module, and resumes legitimate processes.

Abstract: In an example there is provided a method for certifying transactions of a workflow for a workflow comprising a set of transactions and a permitted order of execution of transactions. The method comprises generating verification data in response to a request from a client to certify a transaction of the workflow on the basis of a secure ledger where the verification data certifies the validity of the secure ledger. The method further comprises communicating the verification data to the client. The secure ledger is determined on the basis of workflow transactions.

Abstract: In some examples, there is provided a method, comprising receiving data encrypted using an encryption key, querying a digital ledger sewer for rights associated with the received data, recording, at the digital ledger server, a request to perform an access/process operation on the data, decrypting the data using a decryption key, and determining, using the rights, whether a rendering device is authorised to access and/or process the data.

Abstract: In an example, a method includes receiving a signed message generated by a computing device associated with a private key and a public key. The signed message includes an input message signed with the private key. The method further includes generating, using processing circuitry, a candidate public key based on the input message and the signed message using a public key recovery procedure. The method further includes determining the public key associated with the computing device based on an indication as to whether or not the candidate public key corresponds to the public key associated with the computing device.

Abstract: Examples associated with ransomware attack monitoring are described herein. One example includes a monitor module to monitor files stored on the system for sequences of file accesses that match a predefined pattern of file accesses. An investigation module is activated based on a sequence of file accesses that match the predefined pattern. The investigation module logs actions taken by processes to modify files. A reaction module pauses a set of processes operating on the system based on the logging performed by the investigation module, and resumes legitimate processes.

Abstract: In an example, there is provided a method for creating a workflow, comprising workflow tasks. The method comprises assigning workflow tasks to workers, according to an access control policy. The method comprises encoding as a transaction to a secure ledger that access to the workflow is granted to a worker to perform a workflow task and enforcing access control on execution of the workflow task according to the transaction encoded to the secure ledger.

Abstract: In an example, a machine-readable medium includes instructions that, when executed by a processor, cause the processor to order, as part of an execution of a trusted process, a plurality of processes into a sequence comprising a first process, at least one intermediate process, and a last process. The machine-readable medium may further comprise instruction to cause the processor to generate, as part of an execution of the first process, a value based on a code portion of the process following the first process in the sequence, and to generate, as part of an execution of each intermediate process, a respective value based on the value generated by the process preceding the intermediate process in the sequence and based on a code portion associated with the process following the intermediate process in the sequence.

Abstract: A method comprising: receiving, by a blockchain maintainer, a client request for a cryptographic token, the cryptographic token to allow the client to access a particular service from a service provider; processing, by the blockchain maintainer, the request using a blockchain smart contract to determine if the client request is valid; if the client request is determined to be valid, including the client request in the blockchain; generating, by a token issuer, the requested cryptographic token in response to inclusion of the valid client request in the blockchain; and issuing the generated cryptographic token to the client.

Abstract: Examples associated with ransomware attack monitoring are described. One example includes a monitor module to monitor files stored on the system for sequences of file accesses that match a predefined pattern of file accesses. An investigation module is activated when a number of sequences of file accesses that match the predefined pattern exceeds a first threshold. The investigation module logs actions taken by processes to modify files. A reaction module pauses a set of processes operating on the system when the number of sequences of file accesses that match the predefined pattern exceeds a second threshold. The reaction module then identifies processes associated with a suspected ransomware attack based on the logging performed by the investigation module, and resumes legitimate processes.

Abstract: An apparatus, being a network entity of a computer network is provided. The apparatus comprises a communication module to receive and to send information on a blockchain. Moreover, the apparatus comprises a query module to obtain from a master chain of the blockchain a rule for a first shard and a second shard of the blockchain with respect to a smart contract. Furthermore, the query module is to obtain information on the smart contract from the first shard or from the second shard depending on the rule. Moreover, the query module is to output the information on the smart contract.

Abstract: In an example, print apparatus comprises a security services engine to perform cryptographic services. The security services engine may receive a request for a cryptographic service and validate that the request is an authorised request. On successful validation, the security services engine may perform the cryptographic service by acquiring a first key, acquire an associated first key identifier and may output the first key identifier.

Abstract: A method, in examples, comprises appending multiple workflow transactions to a distributed digital ledger, verifying a sequence of the multiple workflow transactions using verification criteria, generating a certification transaction attesting to the verified sequence of multiple workflow transactions according to a visibility policy, collating multiple certification transactions for respective sequences of workflow transactions, and generating a chained certification transaction.

Abstract: In an example, a machine-readable medium includes instructions that, when executed by a processor, cause the processor to order, as part of an execution of a trusted process, a plurality of processes into a sequence comprising a first process, at least one intermediate process, and a last process. The machine-readable medium may further comprise instruction to cause the processor to generate, as part of an execution of the first process, a value based on a code portion of the process following the first process in the sequence, and to generate, as part of an execution of each intermediate process, a respective value based on the value generated by the process preceding the intermediate process in the sequence and based on a code portion associated with the process following the intermediate process in the sequence.

Abstract: Examples associated with ransomware attack monitoring are described. One example includes a monitor module to monitor files stored on the system for sequences of file accesses that match a predefined pattern of file accesses. An investigation module is activated when a number of sequences of file accesses that match the predefined pattern exceeds a first threshold. The investigation module logs actions taken by processes to modify files. A reaction module pauses a set of processes operating on the system when the number of sequences of file accesses that match the predefined pattern exceeds a second threshold. The reaction module then identifies processes associated with a suspected ransomware attack based on the logging performed by the investigation module, and resumes legitimate processes.