## CryptoDB

### Mingyuan Wang

#### Publications

Year
Venue
Title
2019
CRYPTO
This paper constructs high-rate non-malleable codes in the information-theoretic plain model against tampering functions with bounded locality. We consider $\delta$-local tampering functions; namely, each output bit of the tampering function is a function of (at most) $\delta$ input bits. This work presents the first explicit and efficient rate-1 non-malleable code for $\delta$-local tampering functions, where $\delta =\xi \lg n$ and $\xi <1$ is any positive constant. As a corollary, we construct the first explicit rate-1 non-malleable code against NC$^0$ tampering functions.Before our work, no explicit construction for a constant-rate non-malleable code was known even for the simplest 1-local tampering functions. Ball et al. (EUROCRYPT–2016), and Chattopadhyay and Li (STOC–2017) provided the first explicit non-malleable codes against $\delta$-local tampering functions. However, these constructions are rate-0 even when the tampering functions have 1-locality. In the CRS model, Faust et al. (EUROCRYPT–2014) constructed efficient rate-1 non-malleable codes for $\delta = O(\log n)$ local tampering functions.Our main result is a general compiler that bootstraps a rate-0 non-malleable code against leaky input and output local tampering functions to construct a rate-1 non-malleable code against $\xi \lg n$-local tampering functions, for any positive constant $\xi < 1$. Our explicit construction instantiates this compiler using an appropriate encoding by Ball et al. (EUROCRYPT–2016).

#### Coauthors

Divya Gupta (1)
Hemanta K. Maji (1)