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Questions tagged [blockchain]

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The specific nature of a 51% attack - in relation to a multiple choice question

In a course I'm taking the following question came up: A 51% attack means: A. 51% of the nodes are bots B. 51% of the nodes are hackers C. 51% of the nodes are offline or disabled D. 51% ...
Javed Alam's user avatar
5 votes
3 answers
605 views

Using Proof of Work to slow down login attempts

For a while I've been pondering a user authentication protocol that aims to ensure that a client does some computational work before the server will attempt to authenticate the password. The reason ...
Cruncher's user avatar
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1 vote
0 answers
94 views

ssl\tls public key vs ethereum blockchain public key [closed]

In a ssl/tls, the public key for a domain is included in the ssl/tls certificate that your computer downloaded and stored locally. In the ethereum blockchain ecosystem, the public key is derived from ...
EmilyJ's user avatar
  • 113
1 vote
3 answers
228 views

Is it possible to generate a read-only key for a symmetrical encryption (AES)?

I am working with hardware that can only encrypt with AES. The problem with this is that the message must be publicly verifiable on the blockchain, without the encoding key being exposed. This is the ...
Koray Kaya's user avatar
2 votes
1 answer
148 views

Non-interactive multi key encryption and decryption

I need some serious suggestions on my protocol, specifically for decryption. So the scenario is Organizations A and B encrypt their employees' records with their respective public keys and store them ...
Laila Tul Badar's user avatar
0 votes
0 answers
978 views

Storing a private key in android/ios keychain encrypted or not

In my app, the user must use a private key to sign a transaction (on a blockchain). (It is quite common) I am facing questions regarding how to store my user's private key on the device. I am to use a ...
Raphael St's user avatar
1 vote
2 answers
223 views

How is "Smart Contract" security different?

I am learning smart contract programming on Ethereum (using Solidity) and realizing that security is highly important here. Why? Because of 2 reasons: they deal with high-stake financial transactions, ...
shivams's user avatar
  • 221
3 votes
2 answers
2k views

How do companies manage & store cryptocurrency private keys?

For an individual, I see a some options for storing private keys, such as printing them on paper in a vault, using a hardware wallet, encrypting and storing on the machine, using AWS Secret Manager, ...
kdeva's user avatar
  • 31
0 votes
1 answer
133 views

Ways to encrypt data that will be available to specific clients [closed]

I want to store information on the blockchain, but some part of it is private and must be available to selected clients (for example, users who belong to a common company) How can this be done? The ...
Wen Chiang's user avatar
28 votes
3 answers
12k views

Disadvantages of replacing TCP/IP with blockchain

I read this blog (cached version) (and the related cached tweet) about replacing TCP/IP with blockchain. Tweet: The Internet has a serious fundamental flaw: the transmission control protocol/internet ...
MR.-c's user avatar
  • 457
0 votes
2 answers
190 views

Could blockchain be useful for a protocol to verify content from a trusted publisher in the way I'm thinking of? [closed]

The problem with static software whitelisting is that in the real world, employees with versatile jobs need to run unexpected programs. Company sets up a whitelist to limit what programs can run - ...
J.Todd's user avatar
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1 vote
3 answers
259 views

Use-case for decentralized identifiers (DIDs) with unique identities for each relationship

The W3C working group is working on the standardization of Decentralized Identifiers (DIDs). I watched a video presentation about DIDs and the presenter mentioned several times the possibility of ...
DurandA's user avatar
  • 127
0 votes
2 answers
158 views

Use of distributed ledger/blockchain to stop data exfiltration? [closed]

If all our identities, our data (emails, pictures) are on distributed ledgers/blockchain, can the use of distributed ledgers/blockchain stop data exfiltration for good?
Nathan Aw's user avatar
0 votes
0 answers
442 views

how to document and check apt inrelease files? are there blockchain records for that?

apt InRelease files update like twice every day, in ubuntu repositories and their mirrors. similarly in ubuntu and debian based distros, and other apt repositories. these files are small text files ...
qdinar's user avatar
  • 99
0 votes
1 answer
187 views

Methods to Prove Data Authenticity from Potentially Compromised Sources?

I've been thinking about this problem for some time and I wanted to ask if there are any known methods, or research papers, about how to prove "authenticity" or correctness of data ...
Todd Fulton's user avatar
0 votes
2 answers
375 views

Sign records in a database [closed]

I have a table in my database where I store records to be processed later (basically orders that need to be invoiced or something similar, but this is not the important part). Since this software runs ...
Diego Queiroz's user avatar
0 votes
0 answers
183 views

Blockchain 2FA by sms (wallet code) secure (hack)?

To keep a long story short, I got hacked on my PC by downloading and executing a wrong file. Programs as InterVPN, Cryptobot and HVNC (told by the hacker via google chat) were installed. My accounts (...
BLE's user avatar
  • 11
24 votes
1 answer
3k views

How can I verify Keybase's end-to-end encryption between me and a friend?

The premise of end-to-end encryption (E2EE) is that the client is secure and trustworthy, your end devices is secure and trustworthy, but the network and server need not be trusted. You've read all ...
Luc's user avatar
  • 33k
0 votes
0 answers
151 views

Can/how does blockchain manage ownership and protection of data?

I was wondering, can/should blockchain be used to store data that is insert-only but the data should be readable only to those that where the data was authorized. So I was thinking that a blockchain ...
Archimedes Trajano's user avatar
0 votes
1 answer
242 views

What is the most secured way to store private key on the client's machine

I'm building the equivalent of a blockchain wallet, it is an end-to-end encryption desktop program, the user (client) must be the only one to know his private key, with this private key, he can send ...
Lamouette's user avatar
0 votes
2 answers
341 views

How secure is Libra considering Visa and Mastercard are behind it?

Libra is the upcoming cryptocurrency by Facebook which Facebook claims is supported by variety of tech companies including but not limited to Mastercard, Paypal and Visa. Facebook also enforces a real ...
Thesnake123's user avatar
1 vote
2 answers
367 views

Can a document be digitally signed multiple times, successively by different users?

The question is, if a document that is collaboratively edited, one user per time, could be digitally signed by every editor before it is passed to the next editor. And if yes, could the final receiver ...
user avatar
2 votes
2 answers
547 views

How are UUIDs assigned in P2P protocols

I am learning about P2P in general (mainly blockchain). I know many P2P protocols uses a distributed hash table for node lookup (kademlia) that maps UUIDs of nodes to their addresses. I am curious ...
Tagor's user avatar
  • 125
1 vote
1 answer
1k views

Send and receive files in an air-gapped system

Is it possible to have an air-gapped system which can send and receive files? From a high level perspective, I can't seem to figure out how this can work and I am starting to think it is impossible. ...
oshirowanen's user avatar
1 vote
1 answer
407 views

Blockchain + shared unused bandwidth as the proxy front = ddos mitigated?

Pentesting the new webapp that we have developed before having an external source have a go at it and give us a risk assessment. Now we have come to the portion right at the end; DDOS. For the most ...
Nilo's user avatar
  • 13
0 votes
1 answer
221 views

Is it safe to store user's secure pass-code in database with encrypted form while creating bitcoin wallet?

I would like to create a Bitcoin Wallet. Part of the process is to store public and private keys in encrypted form in server database. All keys I am storing is encrypted using user's passcode. 1) ...
Sagar Shah's user avatar
0 votes
1 answer
2k views

How to make QR Code uncopyable - Scanning of the QR Code at consumer level [closed]

I am designing a Consumer Protection System for import products on Blockchain technology. My Client wants to use QR Code instead of Security Tax Stamp. How can we make QR Code uncopyable at the ...
biltar03's user avatar
0 votes
0 answers
146 views

User specific AES-256 key for file. Retroactive encryption

I may be falling into a classic encryption-problem trap here... I've been developing applications using AES and public/private key encryption for some time so I have a good understanding of straight ...
amlwwalker's user avatar
4 votes
0 answers
171 views

Voting w/ SAML + BlockChain

There are a few grass roots initiatives to introduce blockchain as a ledger for election voting. My criticism of the ones I have seen, at the time I saw them, is that they did not adequately address ...
Jonathon Anderson's user avatar
1 vote
1 answer
217 views

How does blockchain client trust other nodes?

If we consider any blockchain based system (bitcoin, for example), how does initial trust setup works? When a new user wants to join blockchain network, how does the client know that it talks to ...
Tigran's user avatar
  • 113
-4 votes
2 answers
259 views

Private Blockchain VS regular Public-key cryptography [closed]

Private Blockchain (permissioned) VS regular Public-key cryptography: What is the need and add-value of a private blockchain (permissioned) if one can use normal regular public-key cryptography?
Sam's user avatar
  • 1
-1 votes
2 answers
247 views

App to prove that an image is not edited

I want to prove that a photo I will take has not been edited. So I am planning to implement an open source app which uses a "strict image authentication" technique using private key cryptography as ...
Agnel Vishal's user avatar
0 votes
1 answer
454 views

How does the blockchain prevent just theft of data?

I have been reading about blockchain for some time. The basic premise of security of the blockchain, as far as I can tell, is that in a very large network, change in the hash value of one block ...
user avatar
-1 votes
1 answer
780 views

Bypass Censorship and Filtering Using Blockchain Technology [closed]

I heard some people and companies (like Telegram) claiming it's possible to bypass censorship & filtering of internet using Blockchain technology, for example to prevent censorship of a certain ...
Hamid Mohayeji's user avatar
-2 votes
1 answer
799 views

What are your thoughts on the brave browser? [closed]

I have been playing around with it a little bit and going through the specs. What are your thoughts on it? brave.com/ Full disclosure: I am not associated with the project at all. Just a curious ...
Tiny Cookie's user avatar
6 votes
1 answer
198 views

Are there any specific advantages of using a blockchain tech in the data tier of an organization from a information security perspective?

Blockchain seems to be the most talked about tech topic in 2016. A cryptography powered distributed computing technology that has many potential applications. Are there any specific ways / ...
acthota's user avatar
  • 295