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author | Phil Burton <phil@d3r.com> | 2019-02-25 13:37:59 +0000 |
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committer | Phil Burton <phil@d3r.com> | 2019-02-25 13:37:59 +0000 |
commit | 3431e667a5c6475043ebfd97b43a3fdc4b078596 (patch) | |
tree | cd9eb1249e42de8ee1c7e99fd83cb7f091637b7c /day1/second-talk.txt | |
parent | 4e8368f4d847e5c1352302fc53658dfab2c72a9b (diff) |
Diffstat (limited to 'day1/second-talk.txt')
-rw-r--r-- | day1/second-talk.txt | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/day1/second-talk.txt b/day1/second-talk.txt deleted file mode 100644 index 46df43f..0000000 --- a/day1/second-talk.txt +++ /dev/null @@ -1,97 +0,0 @@ -Block chain - -- Block chain is a database -- Bespoke data structure - -"Not crpyto" - -General Purpose block chain: - -Why? -- Data in block is immutable -- Don't edit or remove, you append -- traceability (Auditing / logging) -- Verifiability (Data must be fully valid) -- reproducibility -- decentralisation -- Trust-less (Removes need for trust) -- transparency - -How? -- What type? - - public - will be hacked - - shared - shared ledger - - private -- Cryptography - - pub/rivate keys - - sign information - - verifablity - - Elliptic Curves - - openssl ecparam -list_curves - - Addressing - - can shorten public keys massively - - Hash algorithm - - Integrity - - 2x sha256 (sha256(sha256($data))) - - 4B version, 32B hash of last Block, 32B hash of data block, 4B timestamp, 4B difficulty, 4B nonce - - Merkle tree - binary hash tree - - Merkle path - list of hashes through the tree - - Genesis block - First block in the chain - - Special as it's first - - Prevents exploitation by being hardcoded - -- consensus - - Confidence - - chain forking needs resolution - - bitcoin users longest chain wins - - proof of work / proof of stake - - difficulty is no of zeros that need to be at the start of the hash - - others (proof of burn, proof of time, proof of ....) - - -- Smart contracts - - Programs that are included in the chain - - e.g. A loan paid by the chain - -- Lighting network (drawback off blockhain is it focuses on integrity not perf) - - Off chain transactions with on-chain settlement - -- Not all blockchains are chains - - IOTA Tangle - -- Challenges - - Fault tolerance - - You lose control of public/shared blockchains - - Now way to enforce software updates - - Conflict resolution - - Integration with current systems - - Security - - Cryptography is first and last line of defence - -- Not perfect for: - - scalability - - performance - - throughput - -- Incentives - - Mining in currencies - - Power for money -- Privacy - - Protect data - -- Hard forks -- 51% attacks - -- Right solution for the right kind of problem - -- Event sourcing on steroids - -QUESTIONS -- Any php recommendations? - - No. -- security? - - Store data not values somewhere else - - Encrypt -- Why private blocks? - - Can give public list of hashes for verification - - keep data private |