<p>Due to the rise and practicality of side-channel attacks which can leak partial information of private keys to adversaries, leakage-resilient public-key cryptography that can withstand side-channel attacks has attracted much discussion and attention. Subsequently, many scholars proposed numerous leakage-resilient cryptographic schemes under various public-key cryptographic systems (PKCSs), including public-key infrastructure PKCS (PKI-PKCS), certificateless PKCS (CL-PKCS), and certificate-based PKCS (CB-PKCS). In public-key cryptography, signcryption combines signature with encryption to reduce computation costs while providing both identity authentication (unforgeability) and data encryption (confidentiality). In the past, numerous signcryption schemes under various PKCSs have been proposed. Also, to provide more elastic and practical usage, several heterogeneous signcryption (HSC) schemes have also been presented, in which a sender and a receiver of these schemes belong to heterogeneous PKCSs. However, the existing HSC schemes cannot withstand side-channel attacks. In this paper, we propose a secure leakage-resilient HSC scheme from a sender under PKI-PKCS to a receiver under CB-PKCS, named the LRHSC scheme. Moreover, formal security proofs are made to show that the proposed LRHSC scheme provides unforgeability and confidentiality against two kinds of adversaries that include outsider and malicious authority.</p>