Latest Crypto related questions

While Public exponent is an even number which means Can't get the d in normal way since gcd(e, phi) won't be 1, and in this case only used one prime number for N (multiple uses for one prime number) What is the idea of getting the m,could p = 3 mod 4 be helpful? Thank you for any idea.

Hello I have been receiving Description : Handshake failure after sending client encrypted handshake message to the server. Is there any tools I can use instead of wireshark to detect the source of this problem because wireshark did not really help me at this point.

I was searching for a random seed to use with a pseudo-random number generator (not trying to encrypt anything). I went to the following web sites:

https://www.fourmilab.ch/hotbits/secure_generate.html

https://www.random.org/

It appears that Random.org has a solid history and is not experiencing problems with DDoS attacks because they do not require an API key. I obviously would not want to use anything  ...

I'm trying to do ECDSA signing, and I need to compute

$$\left(k^{-1} \bmod n \cdot (m + d\cdot r) \bmod n\right) \bmod n$$

I'm able to do the inverse function and multiplication in Montgomery form, but how should I add $m$? Does the arithmetic play well if I just converted $m$ to Montgomery form? Alternatively, I could do $m + d\cdot r$ in 512-bit, but things would get quite messy and slow.

Any oth ...

How to use SEAL（Microsoft's HE library） to encrypt a local training model file? Any code demos?

I'm looking for the ability to create a SINGLE CONSTANT shared secret amongst two or more users (a group) AND if a new user is added to such a secured group the new user should also be able to learn the already known and shared secret without the existing users needing to resend any new data or changing the common secret. The new user should only require ONE received piece of data such as with standard  ...

Setting aside legitimate concerns such as lack of CPA security (not to speak of malleability issues) and thus near-universal insuitability of AES-ECB for general purposes, I thought I recalled reading that there is some form of security which ECB has: specifically, when the plaintext comprises entirely uniformly random data, that it gains some form of security. However, I could not easily find thi ...

In the security game between the challenger and the adversary for the security definition of public key encryption, the challenger creates and gives the public key pk to the adversary. The adversary chooses two messages of equal length $m_0$ and $m_1$ and asks the challenger to encode these. Finally, the adversary has to guess which message was encoded.

Isn't it always possible for the adversary to do th ...

In RFC 5869, the definition of HKDF-Expand is given as follows, with the terminating counter value ranging from 1 to (presumably) 255:

The output OKM is calculated as follows:

   N = ceil(L/HashLen)
   T = T(1) | T(2) | T(3) | ... | T(N)
   OKM = first L octets of T

   where:
   T(0) = empty string (zero length)
   T(1) = HMAC-Hash(PRK, T(0) | info | 0x01)
   T(2) = HMAC-Hash(PRK, T(1) | info | 0x02 ...

I have been searching for many days about the time complexity of O(n) for AES (preferably CBC mode). Moreover, I am searching for formal documents like papers/books/standards. I found this paper: https://ieeexplore.ieee.org/document/5945606 that says O(1)... I can't believe that! And this: https://link.springer.com/chapter/10.1007/978-3-319-15943-0_10 that describes attacks complexity on AES... Has anyo ...

There has been a lot of discussion about whitebox cryptography in recent years. However, I haven't found any signs of real world applications using it.

• Are there any real world IT solutions depending on whitebox cryptography as of 2022?
• Is any kind of whitebox cryptography considered secure by any authority (NIST etc.) and openly used in some really critical areas (banking, military, ...)?