Devices can be configured to implement distributed ledgers capable of immutably recording ledger entries that have validated version identifiers. The devices can include network interfaces, memory and processors. Processors can be configured to obtain ledger entries including version identifiers and version authenticator values, determine software versions that correspond to version identifiers, determine that version identifiers are valid based on version authenticator values, obtain challenges using cryptographic systems, wherein challenges are based on ledger entries, and/or broadcast blocks that incorporate ledger entries to securely add blocks to distributed ledgers. Blocks can be capable of being validated by using cryptographic systems to obtain proofs based on challenges.