Abstract: A method of shared key generation between three nodes through a shared communication medium includes performing, with a processor in a first node communicatively connected to a second node and a third node through a shared communication medium, a one-way function using a first shared key between the first node and the second node stored in a memory of the node and a predetermined counter as inputs to generate a first plurality of pseudo-random bits. The method includes generating, with the processor and a transceiver in the first node, a second shared key between the first node and the third node by transmitting each bit in the first plurality of pseudo-random bits to the third node through the shared communication medium simultaneously to transmission of random bits from the third node to the first node.

Abstract: Methods of preparing particles using a sonication device are disclosed. The methods include directing a particle forming solution containing a particle forming liquid and a particle forming agent as a stream into contact with a sonicating tip of a sonication device under conditions sufficient to transform the stream containing the particle forming solution into a plurality of droplets having a substantially uniform size. The plurality of droplets are contacted with a hardening solution under conditions sufficient to solidify the droplets into particles having a substantially uniform particle size which are then recovered. Particles made in accordance with the methods can be solid or semi-solid and range in size from sub-micron to over 100 microns in diameter.

Abstract: In a method of network communication that mitigates denial of service attacks, a server broadcasts cryptographic puzzles with certain time intervals, where each puzzle is only valid for the given time interval. A client receives the puzzle, generates a solution for the puzzle, and sends a network request to the server along with the solution of the puzzle. The server verifies the puzzle solution. If the puzzle solution is valid and received within a designated validity time period, then the server processes the request of the client. The server generates the puzzle and transmits the puzzle to the client before the client generates a request for services from the server.