Linked Questions

2 votes
1 answer

Is using CFB in SIV secure?

Is SIV mode variant equally secure, if you replace CTR mode encryption with full-block CFB mode encryption? CFB seems to be safe with predictable IV: Is using a predictable IV with CFB mode safe or ...
LightBit's user avatar
  • 1,649
11 votes
2 answers

Random data CBC padding scheme?

When using AES in CBC mode, padding is required when the last plaintext block has not the length required by the cipher. Let's say $k$ mode bytes would be required to fill the block. My idea was to ...
HerpDerpington's user avatar
0 votes
0 answers

How Mac-then-encrypt provide security in nonce-misuse setting?

From this, it is clear that Encrypt-then-Mac provides more complete security than Mac-then-Encrypt but some schemes use Mac-then-encrypt to provide nonce-misuse resistance such as SIV (AES-GCM-SIV, ...
hardyrama's user avatar
  • 2,126
0 votes
0 answers

How secure is Encrypt-And-MAC?

From this popular Crypto.SE thread, the general feeling is that Encrypt-Then-MAC is the most secure. From the first answer, the poster says that Encrypt-And-MAC provides integrity of the plaintext. If ...
Evan Su's user avatar
  • 449
2 votes
2 answers

Is E_k(M)||H(m) form of MAC secure?

Would this encryption and signing scenario be considered tamper-proof? ...
Evan Su's user avatar
  • 449
4 votes
2 answers

MAC-then-encrypt in SIGMA protocol for authenticated key exchange

The SIGMA protocol proposed in 2003 and used in TLS 1.3 and IKE stands for "SIGn-and-MAc" and can optionally protect identity using encryption. The SIGMA-I variant illustrated below ...
DurandA's user avatar
  • 453
3 votes
3 answers

Is CTR more secure than CBC?

In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity. A block cipher by itself is only ...
moyu's user avatar
  • 73
1 vote
1 answer

CBC mode works well for input greater than "b" bits. What is that "b" bits?

This post on about block cipher modes of operation, says that one of the advantages of the CBC is that it works well for input greater than b bits. I also saw that in the book "...
Masoud jt's user avatar
  • 165
0 votes
0 answers

authentication by keyed hash function

assume i have: One-key cipher: E. Hash: H My application is authentication. I have a shared secret key with Bob for the One-key cipher. So, when I send an message to Bob, I also send an authentication ...
pianobegginer's user avatar
0 votes
1 answer

What is the advantage of Encrypt-then-MAC over Encrypt & MAC separately the plaintext [duplicate]

For secrecy, authentication & integrity, you can either use CipherText = Encrypt(PlainText) Signature = Hash(PlainText) CipherText = Encrypt(PlainText) Signature = Hash(CipherText) Either ...
user93353's user avatar
  • 2,245
0 votes
0 answers

Why is MAC encrypted in TLS data transmission? [duplicate]

Referring the slide 16 from this link: I want to ask why is MAC encrypted along with the data to be transmitted. Why isn't MAC just appended at the end of encrypted data ?
Jake's user avatar
  • 163
-2 votes
1 answer

What is the difference between Symmetric authentication systems and Symmetric encryption systems? [closed]

I know Symmetric encryption systems. Can someone explain the difference
Zak's user avatar
  • 1
5 votes
2 answers

During padding oracle attack (CBC), how is first byte of plaintext block is obtained?

Imagine conducting a padding oracle attack against CBC mode with 16-byte length blocks, and PKCS#5 used for padding. You start, as always, revealing the last byte of plaintext. Then you iteratively ...
bleg's user avatar
  • 51
0 votes
1 answer

Safely store data before moving to air-gapped machine

This is related to an earlier question, Is it possible to use an algorithm to generate an OTP? I have two machines: A, and B. A is connected to the internet and files are uploaded regularly. B is ...
DatsunBing's user avatar
2 votes
1 answer

Authenticated Encryption mode & AEAD

I'm studying Authenticated encryption with Associated Data (AEAD). My questions are About AE - I heard that when it comes to Encrypt-then-MAC, if an attacker forges the ciphertext then he gets the ...
pioneer's user avatar
  • 325

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