Questions tagged [key-size]
Key size is the size measured in bits of the key used in a cryptographic algorithm.
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Key size for One Time Pad use with QKD
For a practical QKD implementation where OTP has been chosen for encrypting, how are key sizes determined?
Say, for example, Alice wishes to exchange xGB to Bob, then a key management system should ...
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How Helpful is NXP's LRP Encryption Protocol vs AES for short keys?
NXP has a custom (I think) encryption protocol known as "Leakage-Resistant Primitive", or LRP, built on top of AES. I think the goal of this is to basically "expand" the length of ...
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Using longer key with PKCS#5 derive_key() function for AES256? [closed]
I have code where someone made the key 64 bytes (32*2) and passes to the derive_key() function. It then uses the key created for ...
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Would this 3AES-192 scheme achieve 384-bit key security with just a 384-bit key?
For starters, I don't need any don't-roll-your-crypto stuff. We're discussing a hypothetical.
So the idea is 3DES needs 3x the key size and achieves only 2x key size bit security. So using the 3x ...
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Does ECC give the most secure assymetric cipher for a given public key size?
Cracking an ideal block cipher is basically a brute force key enumeration. The complexity of the attack is exponential, growing as $2^b$. Cracking ECC is also exponential, but the cost grows as $2^{\...
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Entropy output from 256-bit Argon2 input [duplicate]
I would like to deterministically derive two different 256-bit keys from a single passphrase -- one used as an ECDSA private key, the other as a symmetric key for AES-GCM.
Would a KDF output ...
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What is the security of XTS block cipher mode of operation if the key is much larger than the block size?
I made two Linux kernel modules of Hasty Pudding Cipher with key size of 16896-bits (16384-bits key + 512-bits tweak also called "spice), one has 512-bits of block size, the other 128-bits.
I ...
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How much can we compress RSA public keys with two equal size factors?
Can we define an RSA variant in which the public key with $n$-bit public modulus $N$ has a compact representation of $\kappa\ll n/2$ bits, with a security argument that it is as safe as regular RSA ...
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Effective key length in Enigma encryption
Each Enigma machine setting induces a certain encryption in the sense of a function from the space of plain texts to the set of cipher texts.
The number of different Enigma machine settings can be ...
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A question about "attacks on MAC key space"
At page 336 in "Handbook of Applied Cryptography - Menezes", I see the sentence
For $n$-bit MAC with $t$-bit key space this requires $2^t$ MAC operations, after which one expects $1+2^{(t-n)...
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Encryption scheme with variable and provable key-length
I'm currently studying the possibility of a novel ransomware technique, where an adversary instead of forcing the victim to pay a ransom, forces them to brute force a key of given length and thus ...
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Securing symmetric ciphers with 56-bit keys
Under the Wassenaar Arrangement and applicable export control law, symmetric cryptography of an (effective) key size of 56 bits or less is (generally) exempted from export control. I am forced to work ...
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Homomorphic Encryption - Integer modulus in HEAAN and key sampling
I am trying to wrap my head around Homomorphic encryption, specifically the HEAAN/CKKS scheme. I am reading through the publication, but I am getting stuck on page 11, namely the KeyGen and Enc ...
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Threshold Paillier encryption key generation time
I have used the threshold version of Paillier encryption without a trusted dealer in an application. I have tested the key generation phase with different security key sizes such as 80, 512, 1024, and ...
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Does this RSA decryption scheme make sense?
A custom file format has a header encrypted with a 2048-bit RSA public key. I need to decrypt it using a 2048-bit RSA private key. The header has 48 bytes, and according to the scheme I got for the ...
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