Linked Questions
21 questions linked to/from Why should I use Authenticated Encryption instead of just encryption?
14
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5
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How do I detect a failed AES-256 decryption programmatically?
I have implemented a simple encryption/decryption program based on AES-256 in CBC mode1.
Actually, it is more precise to describe it as a compression+encryption / decryption+decompression program.
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29
votes
2
answers
32k
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How does a chosen ciphertext attack work, with a simple example?
Can someone please explain - using a simple example - how a chosen ciphertext attack works?
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7
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4
answers
4k
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One Time Pads and "Bit Flip" Attacks
One Time Pads and Vulnerability to "Bit-Flip" Attacks:
I've seen it in this group, and apparently there are a (small) number of voices on the 'net opining that those relying on OTP are essentially "...
- 263
20
votes
1
answer
3k
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Why choose an authenticated encryption mode instead of a separate MAC?
What are cryptographic reasons to choose an authenticated-encryption mode of operation (such as GCM) over a traditional encryption mode plus an independent MAC, or vice versa?
Assume there is no ...
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6
votes
1
answer
3k
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Why is asymmetric encryption IND-CPA?
According to Wikipedia, the IND-CPA game is:
The challenger generates a key pair PK, SK based on some security
parameter k (e.g., a key size in bits), and publishes PK to the
adversary. The ...
- 163
5
votes
3
answers
3k
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Reusing IV in AES for encrypting file
Everyone says that you shouldn't use the same IV and Key.
Is it safe to use the same IV and Key on only one file. EDIT: I will be using CBC or CFB encryption modes so the IV will be updated based on ...
4
votes
1
answer
2k
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SHA-256-based stream cipher
Can anyone comment if the stream cipher described here is safe? The author claims it to be unbreakable, but does not provide any evidence or proof to support this. For completeness, I have reproduced ...
- 263
5
votes
3
answers
980
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What are the benefits of using AEAD algorithms as MAC
I've seen in 2 places where NIST acknowledge the possibility of using AEAD algorithm for MAC (e.g. page 7 section 5.2 of GCM spec, summary for LAEM on page 6 of LWC status report).
And I see 2 ...
- 9,001
2
votes
2
answers
2k
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Is there an encryption scheme that is url-safe AND compact?
I want to be able to encrypt some data like [email protected]|1234|A in a form that I can send to a user as a clickable link like:
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- 123
3
votes
2
answers
748
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How to provide integrity even though using Authenticated Encryption?
Gilles made the following comment here:
using authenticated encryption does not guarantee integrity, only authenticity. You can't detect a rollback.
From what I gathered:
Authenticated Encryption ...
- 9,969
3
votes
2
answers
1k
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When, where, and how to use HMAC
This question may seem like a duplicate of some others, namely this one, but even though that question asked when and how to use HMAC, the answers only addressed what HMAC was and why/how it worked.
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2
votes
1
answer
2k
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Is it possible to split a large AES encrypted string and decrypt the parts one by one?
Due to some platform restrictions our decryption algorithm can only handle up to 1 million bytes. The string we receive is larger, having been generated by AES in cipher block chaining (CBC) mode, ...
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0
votes
3
answers
1k
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Can data over a very low bandwidth channel still be encrypted?
If you have a very low bandwidth channel, can encryption still be used?
Another way of putting this might be, does encrypting well increase the size of the data significantly?
Are there good ...
- 127
6
votes
1
answer
514
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Can you use SHAKE256_XOF with XOR to make a stream cipher?
SHAKE256_XOF is an extendable output function based on SHA3-512. SHAKE256_XOF can be used to create an infinite length bit string with 256-bits of security. For example:
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1
vote
1
answer
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Why use PBKDF2 over SHA-512 to derive AES encryption key? [duplicate]
Suppose I am using user passwords to derive AES-128-CBC encryption key. This key will be used to encrypt some sensitive data for the user so that even the website owner / operator can not decrypt it.
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