Meningkatnya permintaan terhadap produk Toko roti Z&J diikuti munculnya produk tiruan yang merugikan pembeli maupun produsen. Akibatnya, pembeli kesulitan membedakan produk asli dengan produk palsu sehingga berpotensi menurunkan kepercayaan serta menimbulkan risiko kesehatan akibat penggunaan bahan baku yang tidak terstandarisasi. Kondisi ini diperparah dengan proses verifikasi keaslian yang masih dilakukan secara manual dengan mendatangi langsung tempat produksi, sehingga dinilai tidak efisien dan tidak praktis. Penelitian ini bertujuan merancang dan membangun sistem verifikasi keaslian produk berbasis QR Code menggunakan algoritma Elliptic Curve Digital Signature Algorithm (ECDSA) untuk memastikan keaslian produk. Metode pengembangan yang digunakan adalah metode Prototype melalui tahapan analisis kebutuhan, perancangan, evaluasi prototype, implementasi, dan pengujian. Data diperoleh melalui observasi, wawancara, dan studi pustaka. Sistem dikembangkan berbasis web menggunakan Laravel, PHP, dan MySQL. Hasil White Box Testing menunjukkan nilai cyclomatic complexity yang valid pada fungsi generate dan verify signature. Black Box Testing membuktikan seluruh fungsi sistem berjalan sesuai harapan. Hasil User Acceptance Testing (UAT) menunjukkan tingkat penerimaan sebesar 96% oleh admin dan 92,7% oleh pembeli. Penerapan ECDSA pada sistem verifikasi berbasis QR Code menghasilkan aplikasi web yang memungkinkan pembeli memindai QR Code pada kemasan untuk memastikan keaslian produk secara real-time, terbukti efektif mencegah pemalsuan produk dan meningkatkan kepercayaan pembeli.

The increasing demand for Toko roti Z&J products has been followed by the emergence of counterfeit products that harm both consumers and producers. As a result, consumers find it difficult to distinguish genuine products from fake ones, which risks reducing trust and causing health problems due to the use of non-standardized raw materials. This situation is further worsened by the authenticity verification process that is still carried out manually by visiting the production site directly, making it inefficient and impractical. This study aims to design and develop a QR Code-based product authenticity verification system using the Elliptic Curve Digital Signature Algorithm (ECDSA) to ensure product authenticity. The development method used is the Prototype method, covering the stages of requirements analysis, design, prototype evaluation, implementation, and testing. Data were collected through observation, interviews, and literature review. The system was developed as a web-based application using Laravel, PHP, and MySQL. White Box Testing results showed valid cyclomatic complexity values for both the generate and verify signature functions. Black Box Testing confirmed that all system functions performed as expected. User Acceptance Testing (UAT) results indicated an acceptance rate of 96% from the admin and 92.7% from consumers. The implementation of ECDSA in a QR Code-based verification system produces a web application that allows consumers to scan the QR Code on product packaging to ensure product authenticity in real-time, proven effective in preventing product counterfeiting and increasing consumer trust.