Particular systems, methods, and program products for web-based security systems for user authentication and processing in a distributed computing environment are disclosed. A computing sub-system may receive an electronic processing request and a first signed data packet having a first payload that was hashed and encrypted using a first private key. The first payload may comprise first processing output and a first timestamp. The sub-system may verify the first signed data packet by decrypting it using a first public key. The sub-system may execute computing operations to satisfy the electronic processing request, producing second processing output. The sub-system may configure a data packet with a second payload comprising at least the second processing output and a second timestamp. The sub-system may encrypt the second payload using a second private key producing a second signed data packet. The sub-system may transmit to a second sub-system the second signed data packet.