Questions tagged [cmac]
CMAC is a block cipher-based message authentication code algorithm.
59 questions
3
votes
0
answers
66
views
Simplifying AES-SIV if no AAD is present
My goal is to build a simple as possible AES-based Deterministic Authenticated Encryption (DAE) scheme.
If I look at the SIV scheme defined by Rogaway and Shrimpton, they need to define S2V to have ...
- 7,429
3
votes
3
answers
1k
views
Does the padding have to be invertible for MAC security?
I am taking the Online cryptography course by Dan Boneh.
There is a segment that talks about MAC Padding.
Padding is an act of appending bits to the last block of the message for the MAC constructed ...
1
vote
1
answer
268
views
How to generate 24 bytes CMAC using AES-192 or AES-256
Is it possible to generate a 24 bytes CMAC using AES-192 or AES-256 and if so, how?
According to AN10922AN10922.0df,looks like we can generate 24 bytes and 32 bytes key using div constant ?
- 11
5
votes
1
answer
429
views
Robust CMAC-based key derivation function
I need to select a function that will be used as a key derivation function (KDF) and pseudorandom function (PRF) in contexts that I haven't anticipated. It will run on very low-end devices (think ...
1
vote
0
answers
341
views
Quantum-Safe MAC: HMAC and CMAC
If understood right, CMAC is not quantum-safe because it relies on AES-128 (which isn't considered as quantum-safe), while HMAC is, because it relies on SHA3 (which is considered as quantum-safe). Did ...
- 163
1
vote
0
answers
94
views
Construction of a SKE scheme based on a PRF family and on a MAC with UF-CMA security. Is the scheme secure?
Consider the following construction of a SKE scheme $\Pi^*=(Enc^*,Dec^*)$ based on a PRF family $F=\{F_k:\{0,1\}^n\rightarrow \{0,1\}^n\}_{k\in\{0,1\}^\lambda}$ and on a MAC
$ Tag:\{0,1\}^\lambda \...
- 33
1
vote
1
answer
173
views
Is it possible to extend CMAC for ChaCha
CMAC is defined for AES for authentication. My question is pretty simple: is it possible to extend CMAC for ChaCha? Does it even make sense? I cannot find anything related and I am wondering if I am ...
2
votes
2
answers
1k
views
What AES mode does the CMAC use in Secure Channel Protocol 3 (SCP03)?
I am looking to verify a card cryptogram sent from a smart card chip in accordance with SCP03.
According to the SCP03 spec, the CMAC is used to generate a MAC to authenticate messages sent to/from the ...
- 21
2
votes
2
answers
959
views
Is CMAC secure without IV and the same key? (authenticate only)
I am a bit unsure about CMAC and GMAC and maybe someone can help me.
As far as I know, CMAC does not use an IV [SP 800-38B ch. 6.2]. Is it then secure if I use the same key for different messages? ......
- 143
1
vote
1
answer
670
views
Using CMAC instead of hash function for message signing [duplicate]
Generally, when we want to generate a signature for message M we use hash function H, and sign the result of H(M) with the private key. What if instead of hash function H we would use a CMAC with key ...
- 113
1
vote
1
answer
106
views
Why is Masking used in CMAC? [closed]
I am working on masking in CMAC.
If masking is not used, then what will be the behavior of CMAC?
- 11
0
votes
1
answer
121
views
Complexity of deriving message from CMAC vs HMAC when the key is known
From the description of CMAC and HMAC, given the key and the tag, I think it is easy to derive the CMAC message than the HMAC message.
After obtaining the key and tag for CMAC, an intruder can apply ...
0
votes
1
answer
2k
views
How to calculate a hmac and cmac
I'm searching for a simple description that tells me in a schematic way how hmac and cmac is calculated.
So far I found the following:
...
- 39
1
vote
0
answers
298
views
Forgery of the Carter-Wegman MAC
Consider the nonce-based Carter-Wegman MAC which works on key space $K=\{0,1\}^n \times \{0,1\}^n,$ message space $M=\{0,1\}^{mn}$, nonce space $N=\{0,1\}^n$ and the tag space $T=\{0,1\}^n$ as follows:...
- 141
12
votes
0
answers
269
views
Do CCM and EAX provide key commitment?
In an interesting paper called "Partitioning Oracle Attacks" by Julia Len, Paul Grubbs & Thomas Ristenpart an attack is presented on 1.5 pass AEAD schemes that utilize GMAC (GCM, AES-GCM,...
- 97.3k