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Suppose I asked if there's a practical example of merkle trees in the wild. Someone answers, "of course: git." Then 7 troglodyte friends and I jump on github/gi

Suppose I asked if there's a practical example of merkle trees in the wild. Someone answers, "of course: git." Then 7 troglodyte friends and I jump on github/gitlab/whatever (which is super easy because everyone already uses one of these user-friendly services that wrap around git) and immediately see how git helps us develop by leveraging merkle trees. We realize that the merkle trees are leveraged so that we can ensure (most of the time) data integrity in the history of our source code. Thanks, git! Now suppose I asked if there's a practical example of SSS in the wild. Someone answers, "of course: ___." Then 7 troglodyte friends and I jump on ___ (which is super easy because everyone already uses one of these user-friendly services that wrap around ___)and immediately see how ___ helps us develop by leveraging SSS. We realize that SSS is leveraged so that we can ensure ___. Thanks, ___! Fill in the blanks.

petra 8y ago
Fill in: DNSSEC. "Paul Kane -- who lives in the Bradford-on-Avon area -- has been chosen to look after one of seven keys, which will 'restart the world wide web' in the event of a catastrophic event." https://www.schneier.com/blog/archives/2010/07/dnssec_root_key.html https://www.schneier.com/blog/archives/2010/07/dnssec_root_k...
- jancsika 8y ago
  So in the event of a catastrophe, the key holders will restart the hierarchy by using a system no one else has seen but Bruce Schneier guesses is most likely SSS. I was looking for an example a bit more concrete and inspectable than that.
decentralised 8y ago
I won't follow your script, but here's a nodejs implementation of SSS https://github.com/grempe/secrets.js https://github.com/grempe/secrets.js I've seen SSS used in Ethereum smart-contracts before. Grid+ https://blog.gridplus.io/simple-security-with-shamir-secret-sharing-15704166b8be https://blog.gridplus.io/simple-security-with-shamir-secret-... and Blockstack: https://github.com/blockstack/secret-sharing https://github.com/blockstack/secret-sharing and uPort: https://github.com/uport-project/sss-wasm https://github.com/uport-project/sss-wasm come to mind.
- vitalikbuterin 8y ago
  `poly_utils.py` in https://github.com/ethereum/research/tree/master/mimc_stark https://github.com/ethereum/research/tree/master/mimc_stark is a fairly simple one-file general-purpose library for arithmetic over prime fields, including multi-point evaluation and Lagrange interpolation; secret sharing and erasure coding are quite easy to implement with these primitives.
  - decentralised 8y ago
    Thanks for the link, I'll have a look!
andrewflnr 8y ago
Hashicorp Vault: https://www.vaultproject.io/ https://www.vaultproject.io/ It uses SSS for its startup process.
deleted 8y ago
[deleted]
sowbug 8y ago
If you trust your seven friends, then you can use SSS to pass on digital assets after you die. Decide on a policy. For example, 4 of your 7 friends need to agree that you've been dead/incapacitated for 90 days, and that once that happens they should give your digital assets to Recipient R (probably your next of kin). Pick a master passphrase that decrypts something interesting like a passphrase manager database file. Split the master passphrase using a 4-of-7 scheme. Distribute the seven shares to your seven friends (one to each friend). Now you know the passphrase manager won't be compromised before your death unless you are careless with the master passphrase, or four of your seven friends either collude, get hacked, or honor a legal demand to produce the shares. This gets interesting when the digital-asset ownership is determined exclusively by cryptography. The money in your bank account is not such a thing (a suitably official-looking piece of paper will release your money to anyone), but Bitcoin or Ethereum definitely are (no court order or lead pipe can solve the discrete logarithm problem). Such classes of assets are very new. So there are not yet any "practical examples in the wild" that an ordinary person would be likely to recognize.
dsnuh 8y ago
Hashicorp Vault uses SSS as part of its security model for unsealing the data. https://www.vaultproject.io/docs/internals/security.html https://www.vaultproject.io/docs/internals/security.html

petra 8y ago

Fill in: DNSSEC. "Paul Kane -- who lives in the Bradford-on-Avon area -- has been chosen to look after one of seven keys, which will 'restart the world wide web' in the event of a catastrophic event." https://www.schneier.com/blog/archives/2010/07/dnssec_root_key.html https://www.schneier.com/blog/archives/2010/07/dnssec_root_k...

jancsika 8y ago
So in the event of a catastrophe, the key holders will restart the hierarchy by using a system no one else has seen but Bruce Schneier guesses is most likely SSS. I was looking for an example a bit more concrete and inspectable than that.

decentralised 8y ago

I won't follow your script, but here's a nodejs implementation of SSS https://github.com/grempe/secrets.js https://github.com/grempe/secrets.js I've seen SSS used in Ethereum smart-contracts before. Grid+ https://blog.gridplus.io/simple-security-with-shamir-secret-sharing-15704166b8be https://blog.gridplus.io/simple-security-with-shamir-secret-... and Blockstack: https://github.com/blockstack/secret-sharing https://github.com/blockstack/secret-sharing and uPort: https://github.com/uport-project/sss-wasm https://github.com/uport-project/sss-wasm come to mind.

vitalikbuterin 8y ago
`poly_utils.py` in https://github.com/ethereum/research/tree/master/mimc_stark https://github.com/ethereum/research/tree/master/mimc_stark is a fairly simple one-file general-purpose library for arithmetic over prime fields, including multi-point evaluation and Lagrange interpolation; secret sharing and erasure coding are quite easy to implement with these primitives.
- decentralised 8y ago
  Thanks for the link, I'll have a look!

andrewflnr 8y ago

Hashicorp Vault: https://www.vaultproject.io/ https://www.vaultproject.io/ It uses SSS for its startup process.

deleted 8y ago

[deleted]

sowbug 8y ago

If you trust your seven friends, then you can use SSS to pass on digital assets after you die. Decide on a policy. For example, 4 of your 7 friends need to agree that you've been dead/incapacitated for 90 days, and that once that happens they should give your digital assets to Recipient R (probably your next of kin). Pick a master passphrase that decrypts something interesting like a passphrase manager database file. Split the master passphrase using a 4-of-7 scheme. Distribute the seven shares to your seven friends (one to each friend). Now you know the passphrase manager won't be compromised before your death unless you are careless with the master passphrase, or four of your seven friends either collude, get hacked, or honor a legal demand to produce the shares. This gets interesting when the digital-asset ownership is determined exclusively by cryptography. The money in your bank account is not such a thing (a suitably official-looking piece of paper will release your money to anyone), but Bitcoin or Ethereum definitely are (no court order or lead pipe can solve the discrete logarithm problem). Such classes of assets are very new. So there are not yet any "practical examples in the wild" that an ordinary person would be likely to recognize.

dsnuh 8y ago

Hashicorp Vault uses SSS as part of its security model for unsealing the data. https://www.vaultproject.io/docs/internals/security.html https://www.vaultproject.io/docs/internals/security.html