US Patent 11223470 Post-quantum cryptography side chain

A computing entity accesses one or more blocks of a blockchain, encrypts the content of the one or more blocks using a first cryptographic technique to generate one or more first encrypted block values, and writes a first side chain block comprising the one or more first encrypted block values and a first signature to a first side chain. The computing entity accesses at least one of (a) at least one block of a particular second set of one or more second sets of the plurality of blocks or (b) one or more first side chain blocks corresponding to blocks of the second set, encrypts the content of the accessed block(s) using a second cryptographic technique to generate at least one second encrypted block value, and writes a second side chain block comprising the at least one second encrypted block value and a second signature to a second side chain.