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Questions tagged [data-privacy]

Data privacy refers to (cryptographic) methods to prevent the disclosure of sensitive (identifying) information of persons.

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1answer
70 views

How Zero Knowledge Proof enables Privacy By Design [closed]

How does Zero Knowledge Proof (ZKP) enable Privacy By Design?
0
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1answer
59 views

Zero knowledge proof in smart parking managment systems

I read this paper on protecting user privacy in smart parking management system. It talks about using zero knowledge proofs to protect privacy but I am not certain how they do it. My assumption is ...
1
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1answer
41 views

lookup encrypted text by clear text without decryption

I've implemented vouchers module in my web project where I use it to generate redeem get etc... vouchers. since voucher codes are considered sensitive, I've considered to encrypt them using AES-GCM. ...
1
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0answers
33 views

Laplace mechanism from Exponential mechanism in Differential Privacy

In McSherry and Talwar's paper which introduces the exponential mechanism for differential privacy, they say that the Laplace mechanism can be captured by choosing the score function as $q(d,r) = - |f(...
4
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2answers
106 views

Cryptographic scheme where a single message cannot be decrypted but if combined with other it can be

i'm wondering if this type of cryptographic scheme does exists. I know about homomorphic encryption but if one has the private key, he can decrypt every single message. I would like to know if there ...
1
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1answer
52 views

Filter party-1 strings against party-2 white/black list keeping the lists private

Suppose I have a server and a client. The client has a list of arbitrary strings and the server is supposed to filter this list using white and black lists kept on the server side. It would be nice ...
2
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0answers
46 views

End-To-End encryption for VoIP teleconference applications and many-to-many lag-sensitive applications

There are various protocols that allow you to have privacy-enhanced chat. Those can be either 2-party chat such as: OTR SIGNAL or multiparty chat such as: SIGNAL (n+1)sec mpOTR GOTR (2013 spec and ...
1
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1answer
38 views

what can attackers do between two end hosts

I have one question that I couldn't come up with a nice solution. So let's have this analogy, I have a box full of money and I want to deliver to this my friend. Here if we think of a potential ...
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0answers
18 views

Randomized response with more than 2 options

It is well-known that the binary randomized response mechanism is differentially private, with $\varepsilon=ln(3)$ if each person answers truthfully with probability $0.5$, and uniformly randomly ...
3
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1answer
121 views

Difference between ε-differential privacy and (ε, δ)-differential privacy

I don't understand the necessity of introducing the additive term δ in the differential privacy definition. Moreover, reading different papers and blogs they say that because of the δ term the ...
1
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3answers
116 views

Encryption for IOT devices with minimal overhead

I have several IOT devices that transmits nearly 200 bytes of data every 10 seconds. I want to make the data secured but i also want to keep the data size nearly same. Ofcourse for IOT devices ...
1
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1answer
43 views

Is it possible to derive the recipient's public key from libsodium's crypto_box?

Libsodium has "crypto_box_seal" which according to the documentation is used to "anonymously send messages to a recipient given its public key.", which hides the sender. But Is it possible for Eve to ...
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1answer
67 views

Is this construction a secure MAC?

Let $F:\{ 0,1 \}^n \times \{ 0,1 \}^ n \rightarrow Z^*_q $ is a PRF, and $H:\{ 0,1 \}^{2n} \rightarrow \{ 0,1\}^n$ is a secure hash function. Is the following construction $\Pi=(Gen,Mac,Vrfy)$ is a ...
2
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0answers
24 views

Avoiding multiple use of sIgned identities while not learning anything about them

There is an authority A with an associated public/private key pair (A.priv, A.pub). A can issue new "identities" by signing data (numbers or bytestrings). Each number associated with a signature by A ...
1
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1answer
29 views

Divide data into parts and restore from them

I'm not much familiar with cryptography, so please guide me in the right direction on the following question: Let's say I have some data (array of bytes) $D$. I want to convert it into $N$ pieces (...
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0answers
145 views

Leak information (new setting)

This question is similar to Leak Information?, but with new settings. Let $a,b,c,d,e,f$ be selected at random from $\mathbb Z^*_q$. Also, let $r_1,r_2,r_3,z_1,z_2,z_3,p_1,p_2,p_3$ be selected at ...
4
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0answers
113 views

computational indistinguishable/distinguishable?

Let $a,b,c,d$ be selected at random from $Z_q$. Consider the following two distributions $X_1$ and $Y_1$: $X_1={(r_1\cdot a, r_2\cdot b, r_3\cdot c, (r_1+r_2-r_3)\cdot d)}$ where $r_1,r_2,r_3$ ...
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0answers
32 views

Seeking Fast Bloom Filter for Anonymous Address

I had an idea to use something like public message boards to pass secrets anonymously and non-interactively (similar to TV/Movie Trope : http://tvtropes.org/pmwiki/pmwiki.php/Main/PublicSecretMessage )...
3
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1answer
123 views

Secure distance calculation

I am working on securing a feature in a csv file. My goal is to encrypt, anonymize, mask.... etc the content of the records of the feature while preserving the distance between the characters. as ...
2
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0answers
83 views

Merkle tree to prove integrity of subset of data

I'm thinking up a scheme where a merkle tree is used to ensure integrity of a set of data items, and different parties are allowed to verify the integrity of different subsets of that data. Let's ...
1
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0answers
37 views

Any algorithm with a pair of master keys and multiple pairs of subkey for a secure key escrow?

Note: This question looks like my other question — Any algorithm with a master key for decrypting private key encrypted messages? — which is perfectly answered by @real-or-random, but this one is ...
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1answer
308 views

Any algorithm with a master key for decrypting private key encrypted messages?

Are there any algorithm out there that implements following scenario? Create a master private key Create a private/public key #1 based on the master key Create a private/public key #2 based on the ...
1
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1answer
145 views

Is zero IV with AES-CBC safe if CPA is not possible and indistinguishability is not an issue?

Is using zero IVs with AES-CBC safe, if chosen-plaintext attack (CPA) is not possible and ciphertext indistinguishability is not an issue? Practical example: ...
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1answer
91 views

Understanding the big picture with regard to how anonymous credentials work

I'm trying to learn about anonymous credential systems. I started with Lysyanskaya's thesis, which gives an outline of how to build an AC system given some particular primitives (signature scheme, ...
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0answers
79 views

Proving to have sent data, without revealing it

This may be easy, but I'm struggling to find a reasonable solution now. Alice wants to send data to Bob. The data that Alice wants to send has been verified by Carl in some way, even though Carl has ...
2
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1answer
379 views

Is there a hash tree schemea designed for complex data structures?

I have a JSON object with private data. It has the following (complex!) structure: ...
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0answers
79 views

what does differential privacy (in machine learning) promise or guarantee?

I am recently reading some papers about privacy-preserving machine learning. Some works incorporate the idea of differential privacy to protect the privacy of the training dataset when the model is ...
1
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1answer
101 views

Zero-knowledge voting with hidden weights

Assume a voting with delegates, where each delegate's vote $v_i \in \{-1,1\}$ has a certain weight $w_i$ depending on the number of people who elected the delegate. Is there a way to calculate the ...
2
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0answers
42 views

Differential privacy on multiple queries – what is the behavior?

Differential privacy framework still continue to be obscure in the following case: If I make a set of queries, I can join their output to restore the original data. For this issue we have composition ...
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0answers
25 views

Sensitivity of probability measure in differential privacy

I know that we need some sort of sensitivity(global, local) to calculate noise that needs to be added for differential privacy. The noise is the maximum difference between two neighboring datasets. ...
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0answers
22 views

AES CBC Transfer vnitialization vector via HTTP [duplicate]

I'm developing application and there will be functionality to encrypt payload with AES CBC by client, and send it on server for storing. But I need to use random IV every time, to make it reliable. ...
0
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0answers
59 views

Summation that reveals only whether the sum is large

Is there a cryptographic algorithm that can do the following? Clients perform actions that have weight. For example, people making bank transactions, and weight is the absolute value. We would like ...
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1answer
51 views

Increasing Entropy of Limited Information / ID

Supposed that I get an ID from third party (in this case, Telegram ID which is the range $-2^{31}$ to $2^{31}-1$). I want to store the ID securely and privately into my database by hashing it. I don'...
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0answers
57 views

Simulating cloud computing for Partially Homomorphic Cryptosystem

Actually I am a new comer to cryptography and for now I want to simulate Partially Homomorphic Cryptosystem (modified) on cloud computing. If you want some clarity, maybe you would check this paper. ...
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0answers
34 views

Sharing information and privacy in multiparty interaction

I have a problem about sharing information between different partners. Assume there are 3 partners (A, B, C) in the system. A and B are doing a business, and part of the information of the business ...
0
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2answers
123 views

Format Preserving Encryption after compression algorithm?

I have large data set which has sensitive information. I want to encrypt different parts of it with different keys. There is also need for compression as data is very large (100s of GB that has to be ...
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1answer
239 views

Comparing two committed values

Given two commitments on different values, Can a third party compare those two commitments to know which one is the higher value?
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1answer
242 views

Intuitive explanation of the $\varepsilon$ parameter in differential privacy

I think I have a decent intuitive understanding of what the $\delta$ parameter means in $(\varepsilon,\delta)$-differential privacy: I can explain it to a non-specialist in terms of "what are the ...
4
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1answer
279 views

Differential Privacy: why $\delta$ negligible on the row numbers?

The definition of differential privacy says that an algorithm $M$ is $(\epsilon,\delta)$-differentially private if $$P(M(x \in D) \in S)\leq e^\epsilon P(M(x \in D')\in S) + \delta$$ where $D,D'$ ...
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1answer
85 views

Disk/File modes of encryption and authentication [closed]

Secure disk/file encryption has been actively studied over the years. Beside XTS and CBC-ESSIV, are there any other modes of encryption that are commonly used? Which could be the most secure mode? ...
7
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2answers
804 views

Integrity with anti-confidentiality

The Republic of Brutopia are updating the design of their library cards with a new security feature: a 2D barcode containing a cryptographically signed copy of the human-readable fields on the card. ...
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0answers
155 views

Evaluate similarity between two “encrypted” time series

Can you think of any way to evaluate the similarity between two time series without revealing any information on the time series ? More precisely, considering two time series $x$ and $y$ of length ...
12
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1answer
2k views

Applying machine learning algorithms to homomorphic encrypted data

I have a basic understanding of encryption and I got back to the topic because of an interesting site that encrypts financial data using homomorphic encryption (HE) and I would be happy for any input ...
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0answers
51 views

What is the right tool to MPC linear equations system

Given two parties who have private inputes Player 1 - $X_1,...X_n$ Player 2 - $Y_1,...Y_n$ We want to compute a solution to a linear system equation: $f_1(X_1,...X_n,...Y_1,...Y_n) +h_1(X_1,......
2
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0answers
44 views

Can I serve data for user without the ability to access them? Which functions for the user remain?

My Problem I want to serve sesible data for users as a webservice that is accessed by the user via the browser. Restrictions: I may not be able to technically acces the data of the user Data is ...
2
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0answers
295 views

CryptDB data re-encryption and onion layers

From the CryptDB paper , I understoond that the onion layers once decrypted are not re-encrypted. Only columns which are queried infrequently will be re-encrypted to higher onion layers. But if we ...
1
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1answer
243 views

Government root SSL certificate possible vulnerabilities [closed]

I'm writing an article about new government law in Kazakhstan. The law was accepted in December, but now one of our providers announced information for small and medium business how to install ...
3
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0answers
112 views

David Chaum's anonymous credential

I am a newbie in cryptography (I know the basic RSA, AES stuffs) and am interested in anonymous authentication systems. Looks like David Chaum is the godly figure in the field. I see lots of people ...
3
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2answers
94 views

Hiding identifying data while allowing matching?

I do research with people about their illegal drug use, and for one project I'm doing surveys with them when they visit a needle exchange. So over time the same people get repeatedly surveyed as they ...
3
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1answer
555 views

How to enforce data privacy, integrity and authenticity of distributed firmware images for an embedded device?

I'm developing a bootloader for an embedded device, with which it should be possible for customers (i.e. device owners) to update the device's firmware. It is required that: the firmware is ...