multi signatures for blockchains
play

Multi-Signatures for Blockchains Yannick Seurin Agence nationale de - PowerPoint PPT Presentation

Multi-Signatures for Blockchains Yannick Seurin Agence nationale de la scurit des systmes dinformation June 12, 2019 LINCS Blockchain Day Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 1 / 17 Uses of cryptography


  1. Multi-Signatures for Blockchains Yannick Seurin Agence nationale de la sécurité des systèmes d’information June 12, 2019 — LINCS Blockchain Day Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 1 / 17

  2. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  3. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  4. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  5. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  6. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  7. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  8. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  9. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  10. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  11. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  12. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  13. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  14. Uses of cryptography in blockchains • define valid transactions • signatures • multi-, threshold, aggregate, . . . signatures • achieve distributed consensus on the state of the ledger • proof of work: hash functions • proof of stake: • verifiable random functions (VRFs) • verifiable delay functions (VDFs) • proof of space • provide privacy • ring signatures, stealth addresses (Monero) • confidential transactions (homomorphic commitments, range proofs) • zero-knowledge proofs / ZK-SNARKs (Zcash) Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 2 / 17

  15. Bitcoin transactions A Bitcoin transaction spends inputs and creates outputs: • an input consists of a reference to an output of a previous transaction and a signature authorizing spending of this output • an output consists of an amount and a public key txid: e62b0a. . . Inputs Outputs Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 3 / 17

  16. Bitcoin transactions A Bitcoin transaction spends inputs and creates outputs: • an input consists of a reference to an output of a previous transaction and a signature authorizing spending of this output • an output consists of an amount and a public key txid: e62b0a. . . Inputs Outputs 3 BTC prevOut: {txid = 29a5c7. . . , ind=3} sig: 3f4de6. . . 1 BTC prevOut: {txid = 63ba6f. . . , ind=1} sig: f7b6c4. . . 5 BTC prevOut: {txid = e953b0. . . , ind=7} sig: fbb521. . . Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 3 / 17

  17. Bitcoin transactions A Bitcoin transaction spends inputs and creates outputs: • an input consists of a reference to an output of a previous transaction and a signature authorizing spending of this output • an output consists of an amount and a public key txid: e62b0a. . . Inputs Outputs 3 BTC prevOut: {txid = 29a5c7. . . , ind=3} val: 7 BTC sig: 3f4de6. . . pubKey: 601b3a. . . 1 BTC prevOut: {txid = 63ba6f. . . , ind=1} val: 2 BTC sig: f7b6c4. . . pubKey: d781a3. . . 5 BTC prevOut: {txid = e953b0. . . , ind=7} sig: fbb521. . . Y. Seurin (ANSSI) Multi-Signatures for Blockchains 12/06/2019 3 / 17

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend