4 ms·
What is “split-key threshold proxy re-encryption”? Can you give an example of the useful case here; what does this enable? I read the README and the blog post,
by jitl 8y ago
What is “split-key threshold proxy re-encryption”? Can you give an example of the useful case here; what does this enable?
I read the README and the blog post, and found neither contains a “wat is this”. The repo links to an Umbral paper PDF that’s hard to read on mobile - requiring a separate PDF viewer app with tiny font - which also doesn’t contain a concrete example in the abstract.
¯\_(ツ)_/¯ Maybe I’m not the target audience.
- tuxxy 8y agoWe have a more feature-complete reference implementation of Umbral called pyUmbral you may want to look into[0]. We (NuCypher) are using this to build a blockchain privacy layer in the form of a decentralized key management system similar to AWS KMS or Google Cloud KMS. You can read our paper that describes our use-case here: https://www.nucypher.com/whitepapers/english.pdf https://www.nucypher.com/whitepapers/english.pdf 0. https://github.com/nucypher/pyUmbral https://github.com/nucypher/pyUmbral
- mwilkison 8y agoProxy re-encryption (PRE) is a form of public key encryption that allows a semi-trusted proxy to transform ciphertext from being encrypted under one key to another, without learning anything about the underlying plaintext. A "re-encryption key" is used by the proxy to do this transformation. Umbral is a split-key version of PRE, which splits the re-encryption key into many shares. A threshold number of these shares are then required to re-encrypt the data (similar to Shamir’s Secret Sharing). Here's a post describing split-key threshold proxy re-encryption in slightly more detail: https://blog.nucypher.com/unveiling-umbral-3d9d4423cd71 https://blog.nucypher.com/unveiling-umbral-3d9d4423cd71