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An airborne AFMAG demonstration test survey was conducted using the ZTEM™ tipper electromagnetic prospecting system over a known magmatic copper-nickel occurrence in northern Saskatchewan, Canada. These tests were conducted in early 2008 and were flown to test the system's capability to detect the conductive but relatively weakly mineralized sulphide deposits and to define potential extensions at depth. The AFMAG method utilizes naturally occurring audio telluric fields from worldwide sferic activity as its primary field source and is capable of large penetration depths -in the order of hundreds of metres to km. The AFMAG field tests corroborate previously airborne transient electromagnetic, magnetic and ground follow-up EM surveys. 2D forward modelling results agree with the >300m vertical depth extent as defined in subsequent diamond drill testing.

This paper presents a high-speed and low-area accelerator architecture for shared key generation using an elliptic-curve Diffie-Hellman protocol over GF(2233). Concerning the high speed, the proposed architecture employs a two-stage pipelining and a Karatsuba finite field multiplier. The use of pipelining shortens the critical path which ultimately improves the clock frequency. Similarly, the employment of a Karatsuba multiplier decreases the required number of clock cycles. Moreover, an efficient rescheduling of point addition and doubling operations avoids data hazards that appear due to pipelining. Regarding the low area, the proposed architecture computes finite field squaring and inversion operations using the hardware resources of the Karatsuba multiplier. Furthermore, two dedicated controllers are used for efficient control functionalities. The implementation results after place-and-route are provided on Virtex-7, Spartan-7, Artix-7 and Kintex-7 FPGA (field-programmable gate arrays) devices. The utilized FPGA slices are 5102 (on Virtex-7), 5634 (on Spartan-7), 5957 (on Artix-7) and 6102 (on Kintex-7). In addition to this, the time required for one shared-key generation is 31.08 (on Virtex-7), 31.68 (on Spartan-7), 31.28 (on Artix-7) and 32.51 (on Kintex-7). For performance comparison, a figure-of-merit in terms of throughputarea is utilized which shows that the proposed architecture is 963.3 and 2.76 times faster as compared to the related architectures. In terms of latency, the proposed architecture is 302.7 and 132.88 times faster when compared to the most relevant state-of-the-art approaches. The achieved results and performance comparison prove the significance of presented architecture in all those shared key generation applications which require high speed with a low area.

An airborne AFMAG demonstration test survey was conducted using the ZTEM™ tipper electromagnetic prospecting system over an unconformity uranium occurrence in northern Saskatchewan, Canada. These tests were conducted in early 2008 and were flown to test the system's capability to penetrate and define the basement geology below a thick sequence of Athabasca sandstones, as well as defining resistivity structure relating to possible fault-controlled alteration zones. The AFMAG method utilizes naturally occurring audio telluric fields from worldwide sferic activity as its primary field source and is capable of large penetration depths-in the order of hundreds of metres to km. The AFMAG field tests corroborate previous airborne transient electromagnetic and magnetic surveys, and the inferred geology. A 2D inversion algorithm has been developed to account for the air layer required for the ZTEM tipper data. The results agree with the known geology to below >500m.

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