Downloadable software development kits (SDK) for securely managing, sending, receiving, tracking, transferring, transmitting, validating, and verifying messages, information, assets, tokens, and value on a blockchain technology or multichain technology; downloadable software development kits (SDK) for securely managing, sending, receiving, tracking, transferring, transmitting, validating, and verifying messages, information, assets, tokens, and value between blockchain networks or multichain ...