19 ms·

Those are all very good points I didn't think about, thanks for these. I'll fix the two bugs with verify_block and the possibility for a miner to inject invali

by jre 9y ago

Those are all very good points I didn't think about, thanks for these. I'll fix the two bugs with verify_block and the possibility for a miner to inject invalid a output > input transaction. I'll add a note for the 3 others.

westurner 9y ago
For deterministic serialization (~canonicalization), you can use sort_keys=True or serialize OrderedDicts. For deseialization, you'd need object_pairs_hook=collections.OrderedDict. Most current blockchains sign a binary representation with fixed length fields. In terms of JSON, JSON-LD is for graphs and it can be canonicalized. Blockcerts and Chainpoint are JSON-LD specs: > Blockcerts uses the Verifiable Claims MerkleProof2017 signature format, which is based on Chainpoint 2.0. https://github.com/blockchain-certificates/cert-verifier-js/blob/master/README.md#check-certificate-integrity https://github.com/blockchain-certificates/cert-verifier-js/...
- Cyph0n 9y ago
  FYI, dicts are now ordered by default as of Python 3.6.
  - cpburns2009 9y ago
    That's an implementation detail, and shouldn't be relied upon. If you want an ordered dictionary, you should use collections.OrderedDict.
    - Cyph0n 9y ago
      True, but if you need both key ordering and performance, dict is the better option.
    - westurner 9y ago
      It's now the spec for 3.6+. > #python news: @gvanrossum just pronounced that dicts are now guaranteed to retain insertion order. This is the end of a long journey. https://twitter.com/raymondh/status/941709626545864704 https://twitter.com/raymondh/status/941709626545864704 More here: https://www.reddit.com/r/Python/comments/7jyluw/dict_knownordered_versus_ordereddict_an/ https://www.reddit.com/r/Python/comments/7jyluw/dict_knownor... OrderedDicts are backwards-compatible and are guaranteed to maintain order after deletion.

19 ms·

Those are all very good points I didn't think about, thanks for these. I'll fix the two bugs with verify_block and the possibility for a miner to inject invali

by jre 9y ago

westurner 9y ago
For deterministic serialization (~canonicalization), you can use sort_keys=True or serialize OrderedDicts. For deseialization, you'd need object_pairs_hook=collections.OrderedDict. Most current blockchains sign a binary representation with fixed length fields. In terms of JSON, JSON-LD is for graphs and it can be canonicalized. Blockcerts and Chainpoint are JSON-LD specs: > Blockcerts uses the Verifiable Claims MerkleProof2017 signature format, which is based on Chainpoint 2.0. https://github.com/blockchain-certificates/cert-verifier-js/blob/master/README.md#check-certificate-integrity https://github.com/blockchain-certificates/cert-verifier-js/...
- Cyph0n 9y ago
  FYI, dicts are now ordered by default as of Python 3.6.
  - cpburns2009 9y ago
    That's an implementation detail, and shouldn't be relied upon. If you want an ordered dictionary, you should use collections.OrderedDict.
    - Cyph0n 9y ago
      True, but if you need both key ordering and performance, dict is the better option.
    - westurner 9y ago
      It's now the spec for 3.6+. > #python news: @gvanrossum just pronounced that dicts are now guaranteed to retain insertion order. This is the end of a long journey. https://twitter.com/raymondh/status/941709626545864704 https://twitter.com/raymondh/status/941709626545864704 More here: https://www.reddit.com/r/Python/comments/7jyluw/dict_knownordered_versus_ordereddict_an/ https://www.reddit.com/r/Python/comments/7jyluw/dict_knownor... OrderedDicts are backwards-compatible and are guaranteed to maintain order after deletion.