Data integrity and security are among the most essential things in this digital era performance. Digital certificates can be one solution to this problem. This research will develop the architecture of digital certificate verification and validation using blockchain. The blockchain concept for digital certificates uses three stages: requirements planning, workshop design, and implementation. Digital certificate files will be tested based on a scenario in which there could be any changes to those files, such as compressing files, changing data of files, inserting images in the file, and rotating files. This system architecture will detect any changes that could occur to the digital certificate file by using a digital signature, Keccak256 hash algorithm, and blockchain. This research shows that change detection accuracy for digital certificate files is 100%. However, there is a digital signature nature that could reduce the accuracy of change detection, and several solutions can be resolved. The average time to generate a signature using blockchain technology is 2.11 seconds, faster than 3.23 seconds when it does not use blockchain. The average time to validate a signature is 2.11 seconds without using blockchain, which is reduced to 0.22 seconds using blockchain technology. This research concludes that the architecture for digital certificate verification and validation using blockchain technology has successfully improved the security of digital certificates. Testing showed that even minor changes to a digital certificate could affect the signature, ensuring the certificate's integrity. For further research, evaluating the performance of various hash algorithms within the blockchain network is recommended.