adds // the first two and subtracts the last two. var f ringElement for i := 0; i < n; i += 2 { b := B[i/2] b_7, b_6, b_5, b_4 := b>>7, b>>6&1, b>>5&1, b>>4&1 b_3, b_2, b_1, b_0 := b>>3&1, b>>2&1, b>>1&1, b&1 f[i] = fieldSub(fieldElement(b_0+b_1), fieldElement(b_2+b_3)) f[i+1] = fieldSub(fieldElement(b_4+b_5), fieldElement(b_6+b_7)) } return f } // nttElement is an NTT representation, an element of T_q, represented as an // array according to FIPS 203, Section 2.4.4. type nttElement [n]fieldElement...