fe means field element. Here the field is \Z/(2^255-19). An element t, entries t[0]...t[9], represents the integer t[0]+2^26 t[1]+2^51 t[2]+2^77 t[3]+2^102 t[4]+...+2^230 t[9]. Bounds on each ti vary depending on context.
Changes the sign.
Comparing in constant time.
Power by squaring in constant time. Returns f^power
return 1 if f is in {1,3,5,...,q-2} return 0 if f is in {0,2,4,...,q-1}
Create fe from 32 bytes.
See Implementation
fe means field element. Here the field is \Z/(2^255-19). An element t, entries t[0]...t[9], represents the integer t[0]+2^26 t[1]+2^51 t[2]+2^77 t[3]+2^102 t[4]+...+2^230 t[9]. Bounds on each ti vary depending on context.