Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Disclosed are aspects of an untrusted decentralized computing platform that includes an untrusted decentralized database which participant computing systems within the platform reach consensus on an accepted representation thereof. Some aspects of the databased include one or more directed acyclic graphs, which may include cryptographic hash pointers. Some aspects include an untrusted decentralized database architecture that includes two constituent chains. Some aspects of a consensus layer of the untrusted decentralized computing platform alternate a proof of space with a verifiable delay function to reduce compute resource waste relative to systems reliant on compute sources for proofs of work. In some aspects of a consensus layer alternating the proof-of-space and the proof-of-time, a single difficulty factors may be determined by multiplying their difficulty factors together to generate a single variable which accounts for difficulty for both proofs.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: A virtual-machine-based system that may protect the privacy and integrity of application data, even in the event of a total operating system compromise. An application is presented with a normal view of its resources, but the operating system is presented with an encrypted view. This allows the operating system to carry out the complex task of managing an application's resources, without allowing it to read or modify them. Different views of “physical” memory are presented, depending on a context performing the access. An additional dimension of protection beyond the hierarchical protection domains implemented by traditional operating systems and processors is provided.

Abstract: A virtual-machine-based system that may protect the privacy and integrity of application data, even in the event of a total operating system compromise. An application is presented with a normal view of its resources, but the operating system is presented with an encrypted view. This allows the operating system to carry out the complex task of managing an application's resources, without allowing it to read or modify them. Different views of “physical” memory are presented, depending on a context performing the access. An additional dimension of protection beyond the hierarchical protection domains implemented by traditional operating systems and processors is provided.

Abstract: A virtual-machine-based system that may protect the privacy and integrity of application data, even in the event of a total operating system compromise. An application is presented with a normal view of its resources, but the operating system is presented with an encrypted view. This allows the operating system to carry out the complex task of managing an application's resources, without allowing it to read or modify them. Different views of “physical” memory are presented, depending on a context performing the access. An additional dimension of protection beyond the hierarchical protection domains implemented by traditional operating systems and processors is provided.

Abstract: A virtual-machine-based system that may protect the privacy and integrity of application data, even in the event of a total operating system compromise. An application is presented with a normal view of its resources, but the operating system is presented with an encrypted view. This allows the operating system to carry out the complex task of managing an application's resources, without allowing it to read or modify them. Different views of “physical” memory are presented, depending on a context performing the access. An additional dimension of protection beyond the hierarchical protection domains implemented by traditional operating systems and processors is provided.

Abstract: A method for encrypting a passcode is disclosed. In one embodiment, the method includes: receiving an indication of a portion of the passcode from a user; encoding the portion of the passcode; encrypting the encoded portion into ciphertext using a homomorphic encryption system; updating a cumulative encryption string by executing a cumulative operation to aggregate the ciphertext corresponding to the encoded portion into the cumulative encryption string computed for a previous portion of the passcode, wherein the cumulative operation is dictated by a homomorphic property of the homomorphic encryption system; and generating a passcode message based at least in part on the cumulative encryption string, wherein the passcode message includes a message authentication code.

Abstract: A method and system for encrypting a first piece of information M to be sent by a sender [100] to a receiver [110] allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. The sender uses a bilinear map to encrypt a message M, producing ciphertext V to be sent from the sender [100] to the receiver [110]. The receiver [110] uses the bilinear map to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.

Abstract: A virtual-machine-based system that may protect the privacy and integrity of application data, even in the event of a total operating system compromise. An application is presented with a normal view of its resources, but the operating system is presented with an encrypted view. This allows the operating system to carry out the complex task of managing an application's resources, without allowing it to read or modify them. Different views of “physical” memory are presented, depending on a context performing the access. An additional dimension of protection beyond the hierarchical protection domains implemented by traditional operating systems and processors is provided.

Abstract: A system for measuring power consumption by a mobile device corresponding to access of web pages is provided. The system includes: the mobile device, configured to access web pages via a wireless network; a power measurement device connected to a battery of the mobile device, configured to measure parameters related to power consumption; and a server, in communication with the mobile device and the power measurement device, configured to control the mobile device's access of web pages and control the power measurement device's measurement of parameters, to receive measurements from the power measurement device, and to process the received measurements so as to correlate the mobile device's access of a web page with an amount of power consumed corresponding to the mobile device's access of the web page.