网络安全技术电信群楼3-509
网络安全技术 电信群楼3-509
1. WalletHow to store and spend your bitcoins?Each coinis a (address, value) pair on the (public) blockchainStore the public key and corresponding secret signing keyaddress-publickey→secretkeyUse the signing key to spend the coinStoring bitcoins is really all about storing andmanagingBitcoin secretkeys.Security: making sure that nobody else can spend your coinsAvailability:being ableto actually spendyour coins whenyou want to.Convenience: key management should be relatively easy to do
◼ How to store and spend your bitcoins? ◼ Each coin is a (address, value) pair on the (public) blockchain ◼ Store the public key and corresponding secret signing key ❑ 𝑎𝑑𝑑𝑟𝑒𝑠𝑠 → 𝑝𝑢𝑏𝑙𝑖𝑐 𝑘𝑒𝑦 → 𝑠𝑒𝑐𝑟𝑒𝑡 𝑘𝑒𝑦 ◼ Use the signing key to spend the coin ◼ Storing bitcoins is really all about storing and managing Bitcoin secret keys. ◼ Security: making sure that nobody else can spend your coins. ◼ Availability: being able to actually spend your coins when you want to. ◼ Convenience: key management should be relatively easy to do. 1. Wallet
1. WalletSimplesttrivial waystoringthem on a file on your own local device: your computer,your phone, or some other kind of gadget that you carry, or own,or control.Convenience:口Security: If the device is stolen, ..口Availability: If the device is lost, ..口Wallet: A software or hardware that stores andmanages the keys for the ownerSome additional features may be implemented to enhancesecurity,availability,and/orconvenience.ImageawalletHowtohavebettersecurity,availability,and/orconvenience
◼ Simplest trivial way ◼ storing them on a file on your own local device: your computer, your phone, or some other kind of gadget that you carry, or own, or control. ❑ Convenience: ❑ Security: If the device is stolen, . ❑ Availability: If the device is lost, . ◼ Wallet: A software or hardware that stores and manages the keys for the owner ◼ Some additional features may be implemented to enhance security, availability, and/or convenience. ◼ Image a wallet ❑ How to have better security, availability, and/or convenience 1. Wallet
1. WalletWalletAdatabasestoringthepublickeysandprivatekeysAn interface that has the functionalities:Tellsthe ownerhowmanycoinshehas口Allowstheownertospend his coins?Helps the owner to generate new key pairs and the correspondingaddressesShow the owners'transaction history口UsepasswordtoprotectthekeysfrombeingknownbyunauthorizedusersThekeysarestored inencryptedformBackupthewallettothecloud
◼ Wallet ◼ A database storing the public keys and private keys ◼ An interface that has the functionalities: ❑ Tells the owner how many coins he has ❑ Allows the owner to spend his coins ❑ Helps the owner to generate new key pairs and the corresponding addresses ❑ Show the owners’ transaction history ❑ . ◼ Use password to protect the keys from being known by unauthorized users ◼ The keys are stored in encrypted form ◼ Backup the wallet to the cloud ◼ . 1. Wallet
2. Deterministic WalletDeterministic WalletA wallet that all the key pairs can be deterministically from a'seed'MasterPublicKeyProperty:thepublic keys can be derivedfrom a master public key, without needing the (master) secretkey(s)Hierarchy Property: Each (public key, secret key) pair can actas the master key for its sub-organization. Useful for the largecompanieswithhierarchicalorganizationsElectrumWallet>Almosteachbitcoin-likecryptocurrencyhasorisplanningtohavea deterministicwallet
◼ Deterministic Wallet ◼ A wallet that all the key pairs can be deterministically from a `seed’ ◼ Master Public Key Property: the public keys can be derived from a master public key, without needing the (master) secret key(s) ◼ Hierarchy Property : Each (public key, secret key) pair can act as the master key for its sub-organization. Useful for the large companies with hierarchical organizations ➢ Electrum Wallet ➢ Almost each bitcoin-like cryptocurrency has or is planning to have a deterministic wallet. 2. Deterministic Wallet