Questions tagged [dsa]

The Digital Signature Algorithm (DSA) is a United States Federal Government standard or FIPS for digital signatures. It was proposed by the National Institute of Standards and Technology (NIST) in August 1991 for use in their Digital Signature Standard (DSS), specified in FIPS 186, adopted in 1993. A minor revision was issued in 1996 as FIPS 186-1. The standard was expanded further in 2000 as FIPS 186-2 and again in 2009 as FIPS 186-3.

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Is it possible to use non-deterministic ECDSA signatures schemes for signing Ethereum transactions/messages? [migrated]

Is it possible to use a non-deterministic/probabilistic (choosing k randomly and not HMAC-derived from msgHash + privKey like RFC 6979 states) ECDSA signature scheme for Ethereum Signatures? If yes, ...
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Short Nonces in ECDSA signature generation

Recently I noticed that my device generates short-sized Nonces. Approximately $2 ^ {243} - 2^{244}$. Could it turn out that there will be a small leak of ...
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Cryptography (DSA) Get Value of k and private Key

i am on a task in cryptography and need a hint (PLEASE NO SOLUTION). The Task is: I can send Messages (Digital Numbers) to a Docker Container. The response are the values p,q,g,z1,s,r and hashvalue(m+...
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Signing same message 2 times with ECDSA

Can multiple signatures of the same message with the same private key (different nonces) lead to a private key trace?
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Is it possible (and if so how) to make one proof for multiple private keys in ECDSA

Lets say I have a message that needs to be signed by two keys that were generated using ECDSA Is it possible to make a signature that accounts for both keys, meaning I can verify with both and see ...
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Can I know from a Bitcoin public key if the private key is odd or even?

Can I know just from a Bitcoin public key if the private key is odd or even? [moderator note] That is, can we find parity of the private key from a secp256k1 public key?For the original dump of ...
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Why does ECDSA produce a pair of values in its' signature (r,s)?

I was wondering why ecdsa generates a signature in form of a pair (r and s) and why it can't be only one value.
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Can the same public key be used for ECDH and ECDSA [duplicate]

I want to generate a public key that I can use to sign messages and receive messages (using ECDH for exemple). I want to do so to have the smallest payload to share. Is it possible and proved secure ?
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Is RSA the only current practical option for asymmetric encipherment of symmetric keys at rest?

As of 2021, is RSA the only practical (i.e. safe, production-ready) option for asymmetric encipherment of symmetric keys at rest? ECDSA is obviously preferable over RSA in the case of signing, but (...
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Find the product of two sums via SMPC

I'm currently working on a distributed threshold DSA scheme that requires to find the product of two sums via secure multi-party computation. Specifically speaking, every one of $n$ parties $P_i$ ...
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Chinese remainder theorem in ECDSA for parameters in secp256k1?

It is known that it is possible to apply the Chinese remainder theorem and attack RSA under precise conditions. https://tls.mbed.org/public/WSchindler-...
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Is the verification process in ECDSA the same or different from in RSA?

With an RSA key pair, from my understanding, Alice who holds the private key is able to encrypt a message into a signature. She would then send the signature together with her original message to Bob. ...
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Confusion over recovery of privatekey in DSA signature when duplicate value of r occurs

In DSA signature where signing is done via $$s = k^{-1}(H(m) + xr) \mod{q} $$ I understand why if two messages singed by the same private key $x$ use the same $k$ value you can recover the private key ...
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Why check for point-at-infinity during ECDSA verification?

The ECDSA standard mandates that during verification we check that an intermediate calculation does not lead to the point-at-infinity (see Step 5. in this summary on Wikipedia ). But why do we check ...
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Sentinel ("trick") values for lattice attack on DSA with biased k (MSB)

I'm studying lattice attack using this sage script. There are 2 options in script: LSB and MSB. The most interesting option for me is MSB. It recovers private key with less then 100 signatures ...
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Question about coefficient of ECDSA in lattice attack

Update: I made my lattice attack worked finally. As the actual reason is quite complicated I decide to write an answer below to describe how it worked so anyone with similar question might get ...
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Security proof about RFC 6979

In the paper: "The Random Oracle Model: a Twenty-Year Retrospective", section 7.3 by Koblitz & Menezes,the authors tried to prove the security of ECDSA+. But after looking at the entire ...
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Why does RFC 6979 need so many loops?

I recently started reading RFC 6979. I'm curious why it needs so many loops. This post asks a similar question: "RFC 6979 - Why not simply hash the message & the private key for deterministic ...
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Why does deterministic ECDSA (per RFC 6979) include the private key in the generation of k?

It's clear that using the private ECDSA key $x$ as an additional input into the hash algorithm, as specified in RFC 6979, doesn't harm security (assuming HMAC_DRBG is a PRF). But is it necessary? ...
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Randomization of ECDSA signing operations to prevent SCA

A large number of SCA papers that talk about ECDSA mention the need for blinding/randomisation of the signing process, typically with a single-sentence comment about replacing the projective ...
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Gennaro & Goldfeder Key Generation Protocol

As I am going through the “Fast Multiparty Threshold ECDSA with Fast Trustless Setup” paper by Gennaro & Goldfeder, 2018, I am stumbled by the key generation protocol (Sect. 4.1, p.10): In Phase ...
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Verify that x, y coordinates given as hex string are valid points on an Elliptic Curve [duplicate]

Given the following information: "curve": "P-256", "qx": "729C51D177EBE2079A0FB7B0B3C2145159CF81EC61960E642A1744719AA9F913", "qy": "...
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Can the security of ECDSA be compromised by the chosen parameters?

The recommended parameters for a secp256k1 ECDSA curve are: (All values are in hexadecimal) ...
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Coin tosses in the context of commitment schemes

I was reading the “Fast Multiparty Threshold ECDSA with Fast Trustless Setup” paper by Gennaro & Goldfeder, 2018 and I encountered this portion (Sect. 2.4, p.6): This excerpt leaves me slightly ...
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ECDSA Algorithm

Let the curve $$y^2 = x^3 + 3x+ 5$$ be defined on $Z_{19}$ . If my private key is $d=4$ what is my public key for $P=(9,1)$ . If $H(M)=4$, find your ECDSA signature for message. Randomize the ...
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ECDSA for EUF-CMA [duplicate]

If I want to prove that the ECDSA (secp256k1) on the blockchain belongs to EUF-CMA, is there any relevant knowledge or literature explaining this part?
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Question about IETF RFC6979 determinisitc (EC)DSA document section 3.6 additional data k'

In RFC6979, on page 14, Section 3.6 "Variants": o. Additional data may be added to the input of HMAC, concatenated after bits2octets(H(m)): ...
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Schnorr groups allowing fast modular reduction, vs GNFS

I'm looking for Schnorr groups allowing fast modular reduction. Say, using the notation in DSA, with 256-bit prime $q$ and 3072-bit prime $p$, and $p\equiv1\pmod q$. Are there standards, RFC, or other ...
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An "unsafe" curve over RSA? [duplicate]

I'm implementing a token server and considering backing them with ECDSA. The options from the library I'm using expose the NIST curves P-256, P-384, and P-521. The safe curves site does not list P-521,...
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Security of an ECDSA Adaptor Signature Implementation

I'm currently working on an implementation of ECDSA Adaptor Signatures, and part of the signature scheme calls for a NIZK proof to verify knowledge of exponent over two public keys that share a ...
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Is it OK to use r-value from ECDSA signature (r, s) to prevent replay attack?

ECDSA signatures are malleable. Given a valid signature (r, s), one can create a second valid signature by negating the s value. I have searched workaround for this issue, and https://yondon.blog/2019/...
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What is the Lord of the Ring(s): Side Channel Attack and What are the results

A recent Paper to appear on USENIX Security 2021 titled as Lord of the Ring(s): Side Channel Attacks on the CPU On-Chip Ring Interconnect Are Practical by Riccardo Paccagnella Licheng Luo Christopher ...
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How to compare the time of encryption, cracking and verification elliptic curve problem in the same framework?

everyone! As a beginner, I would like to ask you a question. The best algorithm known for cracking (done by anonymous snooper) this problem (Discrete logarithm problem of elliptic curve or ECDSA)is ...
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Elliptic curve in Binary Field implementation

For Elliptic curves defined over $GF(2^n)$, by adding any two points P and Q over $GF(2^n)$ we get the third point over $GF(2^n)$. In Elliptic Curve Digital Signature Algorithm (ECDSA) https://en....
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How did this group discover m wasn't random?

In this video a group of "hackers" describe how they discovered private keys for the PS3 that was using this ECDSA algorithm by discovering that the "random" integer $m$ (or $k$ in ...
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Guarding against vulnerabilities for a digital signature service (RSA )

Lets's say I have a cipher-module / cryptography-service that signs a hash of some unknown payload. What are the possible attacks that I would need to guard against in this context (primarily assuming ...
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ecdsa nonce reuse to compute the private key, modular inverse question

I am following along some cryptography challenges:, in particular ECDSA Nonce Reuse here (second problem): https://blog.coinbase.com/capture-the-coin-cryptography-category-solutions-fe94d82165c5 I ...
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Security level of DSA when $q$ is a 224 bit prime?

What is the security level of DSA algorithm when $q$ is a 224 bit prime? Is it always a simple rule that the security level is the bit length of $q$ divided by two ?
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Calculating ECDSA Private Key From Multiple Signatures With Shared k (random nonce)

I've been experimenting with ECDSA signatures and with how the Sony PS3 private key was leaked. Specifically where: $$k = \frac{z_1 - z_2}{s_1 - s_2}$$ $$d_A = \frac{z_1s_2 - z_2s_1}{k(s_1 - s_2)}$$ ...
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How can the Number Field Sieve attack the discrete log in $\mathbb Z_p^*$ of DSA?

The Digital Signature Algorithm (DSA) uses $L$-bit prime $p$ and $N$-bit prime $q$ with $q| p-1$, i.e., $p = r\cdot q +1$ ( Schnorr group if $r>2$ and safe prime if $r=2$). In a way, the security ...
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DSA parameter selection

In the Digital Signature Algorithm, is there a reason why the larger prime parameter should be an $N$-bit prime where $N$ is a multiple of 64 ? Is this strictly necessary for proper working of the ...
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ECDSA sign test vectors

I've seen a large set of ECDSA test vectors for verification. In addition, I've seen some test vectors from NIST, and those can be found here. Is anyone aware of ECDSA sign test vectors which, if &...
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Understanding multiplication of Shamir secret sharing during threshold (EC)DSA signing

I have been looking at the threshold (EC)DSA schemes for honest majority by Gennaro et al. https://www.sciencedirect.com/science/article/pii/S0890540100928815. In the scheme, there are steps where we ...
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Can ECDSA signature signing and verification process replaces password hashed based login system?

ECDSA or DSA in general was to sign a message or data using private key and verify it using public key, if the attacker/imposter doesn't have the private key then they couldn't sign the message ...
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Does it make any sense to hash parts of a hashing target?

TL;DR; Assuming I'm calculating SHA256 for an ECDSA, does it make sense to do SHA256(item1 + SHA256(item1') + item2 + SHA256(item2') + itemN + SHA256(itemN')) or it'...
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Calculating ECDSA m or k (k or d) when s1 = s2

I recently began to look into some information about obtaining the private key $k$ when two signatures have been produced using the same $m$ and $k$. I've been using the well-publicised information ...
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Calculating the point on the curve during ECDSA signature verification

I'm confused as to how he got (62, 44) as an answer within this article: https://www.coindesk.com/math-behind-bitcoin
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186 views

ECDH/ECDSA key exchange on embedded devices

Two devices are communicating only with each other and shall do this with AES encryption. Both devices are offline, have very limited storage and use a small cryptographic coprocessor which is able to ...
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Problem with the signature of message using ECDSA over GF(2^m)

I'm trying to set up an ECDSA with Elliptic Curves over $\operatorname{GF}(2^m)$ with an example of toy with the following values: Using the Weierstrass equation on binary finite fields. $$E: y^2 + x*...
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Which signature is considered more secure and has less communication cost?

This article uses Elliptic Curve Cryptography, but when it comes to signing and verifying messages it is not using the ECDSA signature algorithm. In the article, they mentioned that the communication ...

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