4.8. func ringDecodeAndDecompr(b *[encodingSize1]byte) ringElement { var f ringElement for i := range f { b_i := b[i/8] >> (i % 8) & 1 const halfQ = (q + 1) / 2 // ⌈q/2⌋, rounded up per FIPS 203, Section 2.3 f[i] = fieldElement(b_i) * halfQ // 0 decompresses to 0, and 1 to ⌈q/2⌋ } return f } // ringCompressAndEncod appends a 128-byte encoding of a ring element to s, // compressing two coefficients per byte. // // It implements Compress₄, according to FIPS 203, Definition 4.7, // followed by ByteEncode₄,...