White-box cryptography aims to protect cryptographic implementations against adversaries with full access to execution environments. The encoding-based white-box implementations in SASAS and ASA constructions without the external encodings are vulnerable to automated side-channel analysis such as differential computation analysis (DCA) and differential fault analysis (DFA). The proposed countermeasures for encoding-based white-box implementations, such as masking and table redundancy, are designed to provide one-side defense against either DCA or DFA. However, these approaches are insecure, and no unified countermeasure capable of simultaneously defending against both DCA and DFA has been proposed. This paper proposes the first encoding-based white-box implementation with an ASASA structure against both DCA and DFA attacks. By decomposing and recombining Sbox layers across rounds, our construction conceals round boundaries while enabling efficient representation via multivariate polynomials. Without the external encoding, the ASA-based first and last rounds inherently resist DFA while remaining vulnerable to DCA. To enhance the DCA resistance, we introduce a cipher-level defense framework integrating anti-DCA Sboxes and anti-DCA/DFA layers. This unified approach provides n-bit security for an n-bit block length cipher against both DCA and DFA attacks. Our work bridges critical gaps in white-box cryptography by enabling ASASA-based encodings and offering combined DCA and DFA countermeasures through novel cipher-level constructions.