Quantities of points on some Edwards curves

The Edwards curves of the form x2 + y2 = 1 dx2y2 are investigated in this article. An exact formula for quantity points on over a field Fp is obtained odd prime numbers p. special attention paid to with exactly p+1 Fp. These called supersingular. They not recommended usage cryptography, because their structure relatively simple. supersingularity curve proved any p 4m+3. Also, some other values d, which equivalent (mod p) supersingular, found.