Industri fashion, khususnya lini produk limited edition, menghadapi ancaman serius dari praktik pemalsuan yang merusak reputasi brand dan nilai eksklusivitas produk. Sistem verifikasi konvensional berbasis basis data terpusat sering kali rentan terhadap manipulasi data dan serangan siber (single point of failure). Penelitian ini bertujuan untuk merancang dan membangun sistem verifikasi keaslian produk yang transparan dan aman bagi Redline Apparel. Solusi yang diusulkan mengintegrasikan teknologi Blockchain Smart Contract dengan algoritma Elliptic Curve Digital Signature Algorithm (ECDSA). Metode pengembangan yang digunakan adalah metode Prototype, yang memungkinkan pengembangan sistem secara evolusioner berdasarkan kebutuhan pengguna. Algoritma ECDSA diimplementasikan untuk menjamin autentikasi melalui skema digital signature, sementara blockchain memastikan integritas data bersifat immutable (tidak dapat diubah). Hasil penelitian menunjukkan bahwa sistem berhasil memvalidasi sumber data produsen dan melindungi informasi produk dari manipulasi pihak tidak sah. Berdasarkan pengujian User Acceptance Testing (UAT), sistem mampu melakukan verifikasi keaslian secara real-time melalui pemindaian QR Code dengan tingkat akurasi 100% untuk kode yang terdaftar. Implementasi ini memberikan rasa aman bagi konsumen dan menjaga nilai eksklusivitas produk limited edition melalui sertifikat keaslian digital yang terdesentralisasi.

The fashion industry, particularly limited edition product lines, faces serious threats from counterfeiting practices that damage brand reputation and product exclusivity. Conventional verification systems based on centralized databases are often vulnerable to data manipulation and cyber-attacks (single point of failure). This research aims to design and develop a transparent and secure product authenticity verification system for Redline Apparel. The proposed solution integrates Blockchain Smart Contract technology with the Elliptic Curve Digital Signature Algorithm (ECDSA). The development method used is the Prototype method, allowing for evolutionary system development based on user needs. The ECDSA algorithm is implemented to guarantee authentication through a digital signature scheme, while blockchain ensures that data integrity is immutable. The results show that the system successfully validates the manufacturer's data source and protects product information from unauthorized manipulation. Based on User Acceptance Testing (UAT), the system is capable of performing real-time authenticity verification via QR Code scanning with a 100% accuracy rate for registered codes. This implementation provides a sense of security for consumers and maintains the exclusivity value of limited edition products through decentralized digital certificates of authenticity.