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Questions tagged [anonymity]

Anonymity describes the state of being unknown or unacknowledged.

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Pros/cons of anonymity when messages are encrypted? [closed]

Let's say I'm making an end-to-end encrypted messaging app with the goal of putting "privacy first." The contents of messages are encrypted, but in the current model, it is still visible to the server ...
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2answers
40 views

Is there any way to check signed documents in a group of people without knowing who signed which?

Let's say there are 3 people A, B, C. Everybody knows their public keys. They sign documents/messages and normally we can know who signed which by checking with their public keys. Is there any way to ...
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1answer
68 views

What is an “anonymous admissible timestamp”?

Can anybody explain the term "anonymous admissible timestamp" to me? Could you show a case where it is useful to apply it? I came across this term in the comments of a question on the StackExchange ...
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38 views

Proofs of security for anonymity in a multi-party setting

I'm looking for material that proves the anonymity of parties in a non-interactive setting. I would like to know if there are simulation based proofs (UC) and property based proofs (game based) for ...
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The semantic security in Anonymous Hierarchical identity-bases encryption?

In Anonymous Hierarchical Identity-Based Encryption (Without Random Oracles) by Boyen, to prove security it defined challenge ciphertext like I actually can't get how does the proof work? Why we ...
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1answer
139 views

Anonymity of Paillier cryptosystem in e-voting system

I'm not an expert so at the moment I'm trying to figure out (at high level) how such cryptosystem would exploit it's homomorphic properties to guarantee anonymity in a e-voting system. As far as i ...
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0answers
45 views

Derive anonymous dsa key-pair from two certificate authorities

Is it possible to derive a dsa key-pair based on two private keys from different/independent "Certificate Authorities" (ca1 and ca2) to sign s.th. which then verifies only that the signature is a ...
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1answer
129 views

Advantages of group signature schemes without encryption over with encryption

Many group signature schemes follow sign-encrypt then prove paradigm, where a membership certificate, is encrypted using some public-key encryption scheme. There are some encryption free group ...
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1answer
75 views

Does an anonymous signature hide the sender's identity from the receiver?

Does an anonymous signature hide the sender's identity from the receiver, or simply just hide the sender's identity from an eavesdropper or third party?
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0answers
38 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 )...
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1answer
42 views

A method to receive payments at obscured addresses [closed]

The background: We assume that coin ownership and payments are recorded on a public ledger. Suppose Alice wants to publish some information to let her receive coins from anyone. But she does not want ...
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0answers
50 views

identify PK in ring signatures by using (t,n)-threshold

Consider a group of $n$ public keys $pk_1,...,pk_n$ with corresponding secret keys $sk_1,...,sk_n$. I'm looking for a cryptographic primitive with the following properties: Ring signature property. ...
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36 views

Is integrity important when building anonymity?

I was thinking about applying an anonymity process based on ECDSA signatures to anonymize blocks of information, not the public-key itself. Using a deterministic form of ECDSA to sign blocks and ...
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1answer
131 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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1answer
95 views

How to anonymously transfer ownership where sender cannot resend

I'm new to cyptography, so I apologize if this is a dumb/impossible goal or has already been answered (I was not able to find it by searching). I wish to devise an anonymous protocol for transferring ...
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1answer
557 views

Is it possible to derive an Ed25519-public-key from an Ed25519-signature?

If you have an Ed25519-signature and the signed message, can you derive the corresponding public-key or is the signature anonymous (except if you already know the public-key of course)?
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1answer
139 views

What are the actual anonymity features of ZCash?

I have looked at their FAQ but I didn't find the answer to this. Having looked at their whitepaper, it seems to me that the main feature of ZCash is that you can't trace where the money came from, ...
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1answer
290 views

How CL-signature can act as positive & additive accumulator?

A paper (http://ieeexplore.ieee.org/abstract/document/7961987/) proposes a Braavos (adaptively sound dynamic positive accumulator). Braavos uses two other accumulators. One is adaptively sound ...
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0answers
125 views

Revocation in Idemix and U-prove

I read some materials about MS u-prove and IBM Idemix. But according to these materials, the opinion about revocation is different. Some materials say that u-prove and idemix do not provide ...
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0answers
75 views

High-latency anonymous communication minimum delay?

High-latency anonymous communication (e.g. Mixmaster and Mixminion) delay messages for a long time using mixers to anonymous communications. I understand that it has applications for email and p2p but ...
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0answers
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Combating Traffic analysis Msc Dissertation ideas [closed]

I have started my MSc dissertation on anonymity (how to beat traffic analysis techniques) and i'm looking for practical ideas. What tactics and software technology would be that guarantees private ...
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1answer
318 views

Check if two anonymously signed messages have the same author

I need digital signature scheme with following rules: Signature is "anonymous" which means it doesn't expose author identity (See papers in this answer. Anonymous RSA version or Boneh-Boyen algorithm ...
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1answer
285 views

What is the difference between “Linkable” and “Traceable” Ring Signatures?

In particular, both papers on Traceable Ring Signatures and Linkable Ring Signatures propose they are fit for the creation of ballots. The Wikipedia Article on Ring Signatures, though, suggests ...
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2answers
268 views

Choice of bilinear group for implementation of BLS signature with NIWI proof?

I am trying to sign the multiple (millions of) different readings but the receiver should not be able to link multiple signed readings together (unlinkability) or with the identity of the signer (...
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2answers
510 views

Alice answering Bob without knowing the question

I'm a student and I don't know how to solve the following problem : Alice is proposing a 10 questions list to Bob. Bob choose only 1 question and wants to know the answer without Alice knowing the ...
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0answers
125 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 ...
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1answer
183 views

State of the art techniques for Anonymous Authentication?

What are the state of the art techniques for Anonymous Authentication? What are the most popular ones? The problem domain I am considering is with respect to different users accessing cloud content; ...
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1answer
142 views

Why is Tor alone not enough to guarantee anonymity for Bitcoin?

Why is Tor alone not enough to guarantee anonymity for Bitcoin? Why do we need the constructions like Zerocoin?
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1answer
120 views

Are Anonymity and Authentication possible together?

Anonymity and authentication look to be seemingly contradictory but are both possible together ? I tried reading couple of papers but could not get the big picture. So what are the major approaches ...
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1answer
815 views

anonymous signature implementation and usage?

This is one of the question asked in my class. Implement a anonymous digital signature. So it means hiding signers information. i could not find any article in anonymous digital signing. Also another ...
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0answers
84 views

During electronic voting, how does one hide the choice from Voting device?

Assume the following: I want to cast a vote during an election through an electronic voting system. For our system we make the assumption that the device one uses to cast the vote is potentially ...
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0answers
127 views

Anonymisation resilient to key leak

Problem statement Elbonian citizens have been issued a card holding a random $B_j\in\{0,1\}^b$, $0\le j<2^n$, $b\ge n+20$ (representative example $b=64$, $n=28$). The habit has grown to use this ...
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1answer
1k views

How do I safely anonymize/hash a unique identifier to protect privacy?

I am building a system to collect a unique identifier (MAC addresses from 802.11 probe requests). The system will have several collection points over a large area, submitting to a central database. I ...
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2answers
279 views

How can one encrypt with RSA (or ElGamal) without revealing whom the ciphertext is intended for?

Imagine Alice wants to encrypt for Bob and post this encryption publicly, so that only Bob can decrypt but no one can other than Alice or Bob tell that the message was encrypted for Bob. The naive ...
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1answer
200 views

Group Signature Scheme without Opening but with Revocation

After reading many papers about group signature schemes, I saw that basically all of them employ the possibility of "signature opening": The Group Manager (GM) can identify any signature made by his ...
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1answer
230 views

Is Bitmessage a Mix network?

I've read the Bitmessage whitepaper and I found it rather lacking on the details, but it promises anonymous routing. Can it be considered a variation on mix-networks, where each peer acts as a mix-...
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0answers
205 views

Can you show how that RSA does/doesn't provide anonymity?

Considering a CPA-secure version of RSA where the ciphertext is just a rundom element from $Z^*_N$. Does that meet the anonymity requirement in which an cpa adversary cannot distinguish between a ...
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1answer
163 views

Private Messaging

Suppose Alice and Bob wants to send messages through Sue without revealing to Eve that the exchange took place. Slightly more formally, I don't want Eve to have any advantage telling if Alice is ...
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0answers
121 views

How does Dissent protect against Sybil Attacks?

Dissent claims to be able to be resistant to Sybil attacks. Dissent seeks to offer accountable anonymity, giving users strong guarantees of anonymity while also protecting online groups or forums ...
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2answers
403 views

Snowden Challenge II: Can we solve Snowden challenge quantumly? [closed]

Suppose that tomorrow is July 7, 2050 and Snowden is still stayed in Sheremetyevo airport. Further, let us suppose that quantum computation and quantum commincation are available to everyone, and ...
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3answers
1k views

Cryptographic Challenge: How to Say Something Confidentially to Snowden?

The Snowden situation raises an intereting cryptograpic problem. At present, how can something be sent confidentially to Snowden? Claim: I have no particular political orientation. The above ...
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1answer
498 views

Tor's integrity verification system?

I am trying to understand the design of Tor(onion router). I am reading the original paper on the 2nd generation onion routing system. Where, under integrity checking on streams, they say, "When Alice ...
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1answer
1k views

Can you identify the public key used to encrypt something?

If I encrypt a string with a public key, does the encrypted ciphertext reveal the public key I used to encrypt it? Basically, I don't want anyone to know who the ciphertext is addressed to. I'm ...
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2answers
171 views

Key Exchange and anonymity issue

If Alice (sender) sends a private message embedded with public key of the Bob(recipient) through onion network, so in this key exchange, does Bob remains anonymous to Alice as Alice knows about the ...
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1answer
289 views

Anonymity in end-to-end encryption

Considering a scenario of anonymous data transfer between seller and buyer using proxies. If we consider that there are three proxies that are being selected by the buyer to obtain data from different ...
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0answers
95 views

Can a LIRA system work with cjdns or other decentralized meshnets?

LIRA (Lightweight Incentivized Routing for Anonymity) is a scheme to incentivize participants in Tor to contribute resources, in particular bandwidth. The paper talks about it being used for Tor. Can ...
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3answers
463 views

What crypto system allows for 3 parties: Party 1 who makes an assertion, Party 2 mutates the assertion, Party 3 validates it

I'm looking for the cryptographic equivalent of a Drivers license where the issuer can be verified, the issuer doesn't need to know who you showed the drivers license to, but also allows per-...
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2answers
210 views

Current Status of mixnets for voting

I am currently doing some research on universally verifiable mixnets, but it seems to me that there are too few papers about them after 2006 or so and most of them come from the team of Douglas ...
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1answer
88 views

Is it possible to create a Bilinear Function with Already Assigned “Multiplicative” Input Groups?

Assume that we have an already assigned Multiplicative Cyclic Group $\mathbb Z_p^*$ with order $q=p-1$, and $p$ is a prime number, is it possible to create a bilinear function $\hat{e}: \mathbb Z_p^* \...
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5answers
4k views

Approach towards anonymous e-voting

I want to implement an internet-based e-voting system. Voters shall be able to cast their vote for one out of n possible candidates. Each candidate has his own ballot-box kept by and at a trustworthy ...