Systems and methods to timestamp and authenticate digital documents using a secure ledger are described. Some implementations can include computer-implemented method to timestamp and authenticate electronic documents. The method can include receiving, by a timestamp and authentication server and from a user device, a unique hash value that is generated at the user device based on a source document and a device identifier of the user device, and verifying, by the timestamp and authentication server, the device identifier. The method can also include, upon verifying the device identifier, inserting, by the timestamp and authentication server, the hash value and the device identifier into a secure ledger, and upon successful insertion into the secure ledger, transmitting, from the timestamp and authentication server to the user device, a success status message including a location in the secure ledger where the hash value was inserted.

Systems and methods of providing immutable records, and immutable ordering of records, in a computing system are disclosed. The computing system can be a member of a blockchain network of a plurality of blockchains. Each block can include a cryptographic digest (or hash) conforming to a minimum degree of difficulty, a nonce by which the cryptographic digest was generated in conformation with the degree of difficulty, and a list of cryptographic digests of most recent blocks of participating neighbor blockchains. Blocks may be passed between blockchains of the plurality of blockchains, which enables each member of the blockchain network to verify an immutable record of data transactions free of the mutual trust requirement of a typical blockchain environment. In conjunction with the generation of each block, an event record may be entered into an event log of the computing system wherein the block was generated. The event record, which may contain actionable instructions, requests, etc., may be transmitted to computing systems of participating neighbor blockchains, where actionable items may be acted upon. Further, the event logs of each computing system may be exchanged, compared, and adjusted to reflect the earliest appearance of each block of each participating neighbor blockchain.

A personal blockchain is generated as a cloud-based software service in a blockchain environment. The personal blockchain immutably archives usage of any device, perhaps as requested by a user. However, some of the usage may be authorized for public disclosure, while other usage may be designated as private and restricted from public disclosure. The public disclosure may permit public ledgering by still other blockchains, thus providing two-way public/private ledgering for improved record keeping. Private usage, though, may only be documented by the personal blockchain.

Systems and methods are described for providing secure storage of data sets while enabling efficient deduplication of data. Each data set can be divided into fixed-length blocks. The plaintext of each block can be convergently encrypted, such as by using a hash of the plaintext as an encryption key, to result in block-level ciphertext that can be stored. If two data sets share blocks, the resulting block-level ciphertext can be expected to overlap, and thus duplicative block-level ciphertexts need not be stored. A manifest can be created to facilitate re-creation of the data set, which manifest identifies the block-level ciphertexts of the data set and a key by which each block-level ciphertext was encrypted. By use of block-level encryption, nearly identical data sets can be largely deduplicated, even if they are not perfectly identical.

A computer-implemented method of auditing drug supply chain data gathered from a distributed ledger is disclosed. The method includes receiving a population of drug product records from the distributed ledger. The method includes receiving a first set of drug product criteria. The method includes determining a weighted probability for one or more drug product records of the population of drug product records. The method includes generating a randomized first subset of drug product records from the population of drug product records based on the weighted probability of the one or more drug product records. Other methods, systems, and the like for unbiased drug selection for audit are also disclosed.

There is provided a cryptographic key determination device for determining one or more cryptographic keys in a cryptographic device, the cryptographic device being configured to execute one or more test programs, the cryptographic device comprising one or more components (11-i), each component (11-i) being configured to generate static and dynamic data, the dynamic data being generated in response to the execution of the one or more test programs, wherein the cryptographic key determination device comprises: a data extraction unit configured to extract at least one part of the static data and at least one part of the dynamic data generated by the one or more components (11-i), and a key generator configured to combine the at least one part of static data and the at least one part of dynamic data, and to determine the one or more cryptographic keys by applying a cryptographic function to the combined data.

Computer-implemented techniques for managing transactions of machine learning algorithm updates are described. In one embodiment, a computer-implemented is provided that comprises receiving, by a system operatively coupled to a processor, a request for an update to a machine learning model associated with a software program, wherein the request is received in accordance with a defined blockchain protocol, and wherein the request comprises model development data used in association with optimization of an instance of the machine learning model. The method further comprises, employing, by the system, a blockchain network to facilitate managing fulfillment of the request.

The secure chain of trust steps to boot-up a computing device are split between the shutdown procedure of the computing device and the boot-up procedure of the computing device to reduce the time required for the computing device to boot-up. The main image associated with a central processing unit of the computing device is validated during the shutdown procedure of the computing device such that the operating system for the central processing unit is available when the computing device receives an action to power on. The boot-up time for the computing device is reduced, which allows the computing device to boot-up within an established time frame.

An example operation may include one or more of identifying a plurality of instances of a blockchain storage request that have been independently submitted by a plurality of clients, respectively, verifying whether execution content of the plurality of instances of the blockchain storage request match, and in response to verifying the match, storing the blockchain storage request within a block among a hash-linked chain of blocks.

A computer-implemented method for transmitting and/or submitting digital content such as feedback for an entity to a blockchain is disclosed. This may be, for example, the Bitcoin blockchain. The method, which is implemented at a first node, includes: submitting, to the blockchain, a first transaction for committing a first quantity of tokens to transfer to a second node associated with the entity, the first transaction having a first output; generating a first content for submission to the blockchain; and submitting, to the blockchain, a second transaction that returns a second quantity of the committed first quantity of tokens to an address associated with the first node, the second transaction having the first output of the first transaction as an input, wherein the first content is used to unlock the first output of the first transaction.