While numerous 3D imaging technologies exist, each addressing niche applications with varying degrees of success, none have achieved the breadth of applicability and impact that digital image sensors have achieved in the 2D imaging world [3][4][5][6][7][8][9][10] . A large-scale two-dimensional array of coherent detector pixels operating as a light detection and ranging (LiDAR) system could serve as a universal 3D imaging platform. Such a system would offer high depth accuracy and immunity to interference from sunlight, as well as the ability to directly measure the velocity of moving objects 11 . However, due to difficulties in providing electrical and 1 photonic connections to every pixel, previous systems have been restricted to fewer than 20 pixels [12][13][14][15] . Here, we demonstrate the first large-scale coherent detector array consisting of 512 (32 × 16) pixels, and its operation in a 3D imaging system. Leveraging recent advances

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The situation is quite serious. After four years of research, there has been no satisfactory way for a group of card sharks to play poker over the phone. Until now. In this paper, we present a new method for playing 'mental poker,' discuss its significance, and mention some of the further questions it r a b s. Ante up. The rules for mental poker are just like regular poker, except that players communicate over the phone, and there are no physical cards. The hard part of mental poker is dealing the cards. Hands must be random and disjoint, and players should not be able to claim to have any cards but those dealt (a sleeve will hold as many 'virtual cards' as angels will fit on the head of a pin). Playing mental poker is a difficult problem for a number of reasons. The foremost reason is that it is impossible, a result due to Shamir, Rivest and Adleman.['l Of course, this is an information-theoretic result, and the same reference presents a method for playing mental poker that relies on the difficulty of inverting certain cryptographic transformations. Unfortunately, a cryptographic flaw allows players to determine the color of each other's cards.['] This set the stage for a new implementation devised by Goldwasser and Micali, which was proven to hide all partial information (up to an explicit cryptographic assumption) ,[31 Unfortunately, this implementation works only for two players, which is a very restricted kind of poker. Next, Barany and Furedi devised a protocol that permits three or more players to play poker,[41 but only if players are not permitted to form coalitions. If two players conspire, they can learn the contents of everyone else's hands. The following section discusses this history of mental poker in more detail, outlining the key ideas, contributions and limitations of this earlier work. This paper presents a new way of playing mental poker. Unlike earlier solutions, it is secure against coalitions, permits any number of players, and uses inexpensive, highly secure cryptographic techniques. The protocol does require the participation of a trusted party to shuffle the cards. However, thereafter the trusted party does not participate in the protocol. The protocol can be easily adapted to play almost

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