Symmetric cryptography provides the best examples of cryptosystems to be applied in lightweight environments (e.g., IoT). A representative example is the cryptosystem TinyJambu, one of the ten finalists in the NIST Lightweight Cryptography Standardization Project. It is an authentication encryption with associated data scheme that is extremely lightweight and fast. In this work, we analyze the security of TinyJambu from two distinct and non-symmetric points of view: (1) the improvement of the best cryptanalytical attack found in the literature and (2) a randomness analysis of the generated sequences. Concerning item (1), we launched a differential forgery attack with probability 2^−65.9487, which was improved considerably compared with previous numerical results. Concerning item (2), we analyzed the degree of randomness of the TinyJambu keystream sequences with a complete and powerful battery of statistical tests. This non-symmetric study shows the weakness of TinyJambu against cryptanalytic attacks as well as the strength of TinyJambu against statistical analysis.

Boolean functions and binary sequences are fundamental tools in cryptography. In this work, we introduce a new bijection between the set of Boolean functions and the set of binary sequences whose period is a power of two. This correspondence enables the study of properties of Boolean functions through binary sequences and vice versa. Building on this connection, we propose a novel algebraic description, derived from the algebraic normal form of Boolean functions, which we call the reverse-ANF. Then, we explore how this formulation relates both to existing representations of Boolean functions and to binary sequences. Moreover, several cryptographic properties are examined through this new approach. Finally, we analyse generalized self-shrunken sequences from the perspective of Boolean functions, highlighting several properties that emerge under these different frameworks.