User knaccc

17 votes

1 answer

4k views

After ECDH with Curve25519, is it pointless to use anything stronger than AES-128?

asked Jun 3, 2018 at 22:00

10 votes

2 answers

4k views

Why are NaCl secret keys 64 bytes for signing, but 32 bytes for box?

asked Dec 31, 2017 at 10:20

8 votes

1 answer

320 views

Bob has an EC key pair. How can he receive a small integer in the least compute intensive way?

asked Feb 13, 2017 at 2:19

6 votes

1 answer

560 views

HKDF randomness extraction - salt or no salt?

asked Jan 6, 2022 at 2:08

5 votes

1 answer

193 views

Can elliptic curve point common factors be detected?

asked Feb 17, 2017 at 4:30

5 votes

2 answers

184 views

EC: How to prevent discovery of base point after commutative operation

asked Feb 9, 2017 at 18:13

4 votes

2 answers

930 views

Is it safe to generate two 256-bit ECC keys from 128 bits of entropy?

asked Mar 16, 2018 at 17:10

4 votes

1 answer

1k views

How to use a random 32 byte sequence as a curve25519 public key

asked Sep 22, 2017 at 8:40

3 votes

1 answer

240 views

Why do curve25519 implementations only have ge_frombytes_negate_vartime, and not a regular ge_frombytes method?

asked Sep 23, 2017 at 13:46

3 votes

0 answers

93 views

Which safe elliptic curves allow for the fastest scalar multiplication

asked Sep 14, 2017 at 6:43

3 votes

1 answer

894 views

How many points are there on the X25519 curves?

asked Jun 22, 2018 at 14:01

3 votes

2 answers

275 views

How to prove that two EC public keys created with two different generators share the same secret key?

asked May 16, 2018 at 15:34

3 votes

2 answers

245 views

How to efficiently find the distance between two EC point private keys

asked Feb 13, 2022 at 4:46

2 votes

1 answer

190 views

Discovery of Ed25519 128-bit private key where a KDF has not been used

asked Jul 17, 2022 at 5:58

2 votes

1 answer

95 views

Security level of the hash of the sum of two uniformly random keys

asked Jul 19, 2022 at 14:43

2 votes

1 answer

73 views

Are the following asymmetric encryption schemes equivalent?

asked Oct 2, 2018 at 2:22

2 votes

1 answer

1k views

Why is SHA384 used in TLS cipher suites for AES_256_GCM instead of SHA256?

asked Jan 21, 2022 at 23:03

2 votes

1 answer

2k views

How to convert from curve25519 33 byte to 32 byte representation

asked Sep 21, 2017 at 20:48

1 vote

3 answers

1k views

How to deterministically generate a 256 bit ECC key from 128 bits of entropy without a CSPRNG

asked Mar 18, 2018 at 11:27

1 vote

0 answers

41 views

Is partial computation of an Ed25519 Diffie-Hellman shared secret possible?

asked Jan 29, 2022 at 18:47

1 vote

1 answer

130 views

How to most inexpensively extract 1 byte of uniformly distributed entropy from a 32-byte Curve25519 EC point

asked Jan 31, 2022 at 16:16

1 vote

1 answer

100 views

Would discrete-log-based signing and encryption have been a better choice than RSA?

asked Jan 4, 2022 at 15:27

1 vote

1 answer

47 views

Necessary Schnorr signature non-interactive challenge bindings

asked Mar 10, 2022 at 18:33

0 votes

1 answer

1k views

Reasoning about WebCrypto ECDSA choices: P-256/384/521, SHA-1/256/384/512?

asked Jun 12, 2019 at 0:27

0 votes

1 answer

120 views

What is the term to describe the combination of ciphertext, IV and authentication tag?

asked Aug 9, 2021 at 17:36

0 votes

1 answer

381 views

Can TweetNaCl box sender's private key be set to "1" without privacy loss?

asked May 4, 2017 at 1:17

Stack Exchange Network

26 Questions

After ECDH with Curve25519, is it pointless to use anything stronger than AES-128?

Why are NaCl secret keys 64 bytes for signing, but 32 bytes for box?

Bob has an EC key pair. How can he receive a small integer in the least compute intensive way?

HKDF randomness extraction - salt or no salt?

Can elliptic curve point common factors be detected?

EC: How to prevent discovery of base point after commutative operation

Is it safe to generate two 256-bit ECC keys from 128 bits of entropy?

How to use a random 32 byte sequence as a curve25519 public key

Why do curve25519 implementations only have ge_frombytes_negate_vartime, and not a regular ge_frombytes method?

Which safe elliptic curves allow for the fastest scalar multiplication

How many points are there on the X25519 curves?

How to prove that two EC public keys created with two different generators share the same secret key?

How to efficiently find the distance between two EC point private keys

Discovery of Ed25519 128-bit private key where a KDF has not been used

Security level of the hash of the sum of two uniformly random keys

Are the following asymmetric encryption schemes equivalent?

Why is SHA384 used in TLS cipher suites for AES_256_GCM instead of SHA256?

How to convert from curve25519 33 byte to 32 byte representation

How to deterministically generate a 256 bit ECC key from 128 bits of entropy without a CSPRNG

Is partial computation of an Ed25519 Diffie-Hellman shared secret possible?

How to most inexpensively extract 1 byte of uniformly distributed entropy from a 32-byte Curve25519 EC point

Would discrete-log-based signing and encryption have been a better choice than RSA?

Necessary Schnorr signature non-interactive challenge bindings

Reasoning about WebCrypto ECDSA choices: P-256/384/521, SHA-1/256/384/512?

What is the term to describe the combination of ciphertext, IV and authentication tag?

Can TweetNaCl box sender's private key be set to "1" without privacy loss?