VSS
Distributed Systems @ HSR
Distributed Systems @ HSR
Kartei Details
| Karten | 61 |
|---|---|
| Sprache | Deutsch |
| Kategorie | Informatik |
| Stufe | Universität |
| Erstellt / Aktualisiert | 06.08.2020 / 10.08.2020 |
| Weblink |
https://card2brain.ch/box/20200806_vss
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| Einbinden |
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Which of the following is true for docker?
Which of the following is true about bitcoin?
How many transactions a day is the bitcoin blockchain capable of?
450'000
The address of a bitcoin wallet is also the ...
public key
What is used to sign transactions in bitcoin?
The private key
Name differences between BTC and ETH
- BTC UTXO-based, ETH account-based
- Future: BTC Proof of Work, ETH Proof of Stake
- BTC block rewarded adjusted by rules, ETC block reward adjusted manually
- BTC smart contracts not touring complete, ETH smart contracts touring complete
What are some properties of UTXO-based blockchains?
- every referenced input must be valid and not yet spent
- total value of inputs must equal or exceed total value of outputs
- transaction must have signature matching owner of input(s)
What are some properties of account-based blockchains?
- global state stores list of account with balances and code
- transaction is valid if sending account has enough balance
- if receiving account has code, code runs, state may be changed
What are atomic swaps?
an atomic cross-chain swap is a distributed coordination task where multiple parties exchange assets across multiple blockchains, e.g. BTC for ETH
What does DNSSEC ensure, what does it not ensure?
- ensures that a DNS entry wasn't modified
- provides integrity, but not availability or confidentiality
How does DNS over HTTP work?
- requests are made via HTTP
- responses returned in UDP HTTPS response
- protected from man-in-the-middle attacks
How does DNS over TLS work?
Uses the TLS protocol for DNS queries.
[Prüfungsvorbereitung Beispiel Frage]
Diese daten müssen möglichst effizient übertragen werden versuchen sie mal so ein Protokoll zu entwickeln
TODO
What are the advantages of DoH?
- confidentiality of lookups during transit
- HTTP/2 port 443
- Cannot distinguish between traffic/DNS
- responses served like simple web pages
- Performance: TCP+TLS handshake → 2/3 RTT
- DNS queries from JavaScript
List some facts about DoT.
- confidentiality of lookups during transit
- DNS over TLS port 853
- Widely supported
- Performance: TCP+TLS handshake → 2/3 RTT
- Easy upgrade clients can test if the configured resolver supports DoT on port 853, fall back to DoU53 otherwise)
List some facts about DNS load balancing.
- round robin
- split horizon DNS possible (different answer depending on source of request)
- anycast possible
On which layers can software loadbalancers operate?
Give a definition of load balancing.
Load balancing is the distribution of workloads (requests) across multiple computing resources (machines).
Should distributed systems hide their distributed nature?
How many transactions is the Ethereum blockchain capable of per day?
~826'000
How big is a block in Ethereum?
~25KB
