Symmetric 2-Adic Complexity of Binary Sequences with Interleaving Cascade Structure from Legendre Sequence Pair

Symmetric 2-adic complexity stands out as a better measure for appraising the strength of a periodic sequence against the rational approximation attack. In this letter, we determine the symmetric 2-adic complexity of a class of interleaving cascade binary sequences with period 4N (where N ≡ 3 (mod 4)), which was introduced recently. Our results indicate that the symmetric 2-adic complexity of these sequences is not less than 2N.