Tagged Questions
1
vote
1answer
83 views
How much data can I encrypt with AES before I need to change the key in CBC mode?
In my cryptography class, the instructor suggested that in order to give the attacker a minimal advantage of $1/2^{32}$, we have to change the key after $2^{48}$ blocks are encrypted.
It seems that ...
3
votes
2answers
183 views
AES - plaintext is smaller 128 bit - how to expaned?
we are currently developing a little AES implementation in a crypto-course at university.
As far as I know, AES uses 128 bit blocklength, so all data that will be encrypted will get split up into ...
2
votes
0answers
97 views
Single-purpose symmetric encryption scheme for single files
I'm writing a simple password manager program that will encrypt/decrypt a single file (it's size will most likely stay under a few K). This is my initial file format design:
...
1
vote
1answer
87 views
Partial decryption of large file in AES-GCM (or other modes)?
Lets assume
a 4gig file that is internally made of 1 million pages of 4k bytes each (page).
the file was originally AES-GCM encrypted
these pages (or entire file) lives across the internet i.e. ...
1
vote
2answers
413 views
Is AES in CBC mode secure if a known and/or fixed IV is used?
I have a need to encrypt credentials for a third-party app used by a secured internal app. Over on ITSec.SE, I was helpfully shown a scheme to encrypt the third-party credentials based on a hash of ...
0
votes
1answer
196 views
File Encryption/Decryption in ECB mode [duplicate]
Possible Duplicate:
Removing Padded Value in Decrypted Message
I tried to encrypt and decrypt a file in ECB mode using AES Algorithm but I encountered one problem during decryption, I don't ...
1
vote
1answer
914 views
Cipher Feedback Mode
I can't understand what CFB really is. It said in Wikipedia that CFB is same as CBC, but I find that CFB is more difficult than CBC.
Can someone explain to me how CFB works. Such as how ...
-3
votes
1answer
424 views
Advantages of each encryption mode [closed]
What is the advantages of each encryption mode to other encryption mode..
for example what are advantages of CBC to PCBC, CBC to CFB
just like that.
so that I can filter what would be the best ...
3
votes
1answer
724 views
Does AES-CTR require an IV for any purpose other than distinguishing identical inputs?
I'd like to encrypt files deterministically, such that any users encrypting the same plaintext will use the same key and end up with the same ciphertext. The ciphertext should be private as long as ...
4
votes
2answers
209 views
Is it safe to store initial counter value for AES-CTR alongside with ciphertext?
The initial counter value can actually be thought of as a sort of IV, which I assume is safe to transmit with the ciphertext, but I really want to be sure that this is indeed safe.
7
votes
2answers
2k views
AES in ECB mode weakness
In a project that I'm currently working on, we are encrypting some data using AES with ECB mode in a database. Each piece of data being encrypted is very small, no more than 10 characters long.
Very ...
10
votes
3answers
542 views
Is CBC really dead?
I developed a p2p-app in C# which sends and receives encrypted text messages (50KB). For encryption, my app uses AES 128 bit in CBC cipher mode. For each message it uses a new randomly-generated IV.
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