Questions tagged [output-size]

Output size refers to the output size of specific cryptographic functions. It is especially relevant when the output must fit into a resource constrained system or protocol. For signatures it is the signature size, for KEM schemes it is the size of the encapsulated key.

Filter by
Sorted by
Tagged with
1 vote
2 answers
136 views

Name for number of output values a hash function can produce?

Any hash function has fixed output size but it does not mean that all values of output values are ever used. What's the term for the size of output set? As an aside: Can it be calculated? How do most ...
Euri Pinhollow's user avatar
0 votes
2 answers
200 views

ChaCha20-Poly1305 and AES-GCM-SIV output size

Background information: I need to encrypt 168bit messages, the ciphertext should, preferably, match the plaintext size. Message Authentication and Integrity is not a must, but a really important ...
Florebol's user avatar
2 votes
1 answer
595 views

Is there a simple formula to calculate how many inputs generate same outputs in cryptographic hash functions, being the input larger than the input?

Let's suppose I hash a 384-bits message with a cryptographic hash function and generate a hash digest of 128-bits. I know that due to the pigeonhole principle, many inputs of same size will result in ...
alpominth's user avatar
  • 391
9 votes
3 answers
2k views

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 ...
Maksym Shcherban's user avatar
1 vote
2 answers
525 views

Size of signature

I was wondering what is typically the size of digital signature for every 1-bit data that is signed. I am trying to figure out how size of messages increases if I send only the data in a message or ...
MitterD.'s user avatar
0 votes
0 answers
32 views

Has reducing MAC size and increasing message size the same effect on security?

I am evaluating ways to reduce the overhead of (H)MACs on small messages. I was primarily wondering if there is a difference between halving the MAC length or keeping the same MAC length but using it ...
Septatrix's user avatar
  • 101
3 votes
1 answer
342 views

Why are the parameters (such as modulus and dimension) of homomorphic encryption so large?

Compared with the common lattice-based PQC schemes, the modulus $q$ and dimension $n$ of homomorphic encryption are so large. For example, in Kyber, $n=256, n \times k = \{512,768,1024\}$, $q = 12289$...
WAN Lipeng's user avatar
3 votes
1 answer
192 views

What hash based digital signature algorithms exist that have reasonably small signature sizes?

What hash based digital signature algorithms exist that have reasonably small signature sizes? By reasonably small, I mean not much bigger than what you would get with a 256-bit ECDSA (which I ...
user4574's user avatar
  • 133
2 votes
1 answer
340 views

Size of group elements in a bilinear context

In a asymetric pairing context, which size (in bits) should have the elements of $\mathbb{G}_1,\mathbb{G}_2$ and $\mathbb{G}_T$ if we consider the most efficient elliptic curves?
Ievgeni's user avatar
  • 2,575
5 votes
1 answer
507 views

What are the public key and output sizes for the four remaining PQC KEM candidates?

Currently there are only 4 direct candidates left that provide KEM. Generally performance seems to be "OK" for those candidates. However, the key and encapsulated key sizes (i.e. the output ...
Maarten Bodewes's user avatar
  • 92.3k
1 vote
1 answer
176 views

Is there an asymetric encryption whos output size is quite equal to the input size

I want to send a verifiable chunk of data (around 16 bytes) by simply encrypting it with a private RSA key, providing the public key in the source code for the verification. This was my initial ...
AquilaRapax's user avatar
1 vote
1 answer
3k views

Is there a way or how to predict the output size as a result of encryption?

Is there a way or how to predict the output size as a result of encryption from 3DES, AES-128, AES-192 etc ? So that I know how to store them in the data in DB given a known possible clear text length....
wei3923's user avatar
  • 321
3 votes
1 answer
585 views

PBKDF2 output size vs internal hashing algorithm

PBKDF2 allows you to choose an output size as well as the internal hashing function used. My question is, do these two sizes need to match? For example, if I'm using PBKDF2 with SHA512, does my ...
Snowman's user avatar
  • 363