Bitcoin
Bitcoin Core integration/staging tree
...By default, you will need to store all of that data, but if you enable pruning, you can store as little as 6GB total without sacrificing any security. For more information about setting up Bitcoin Core, please read the full node guide. Download verification is optional but highly recommended. Performing the verification steps here ensures that you have not downloaded an unexpected or tampered version of Bitcoin, which may result in loss of funds. Experienced users who don't mind performing additional steps can take advantage of Bitcoin Core's reproducible builds and the signed checksums generated by contributors who perform those builds.