(or Advanced Encryption Standard), a symmetrical block-cipher algorithm with a 128-bit block size, and key sizes of 128, 192 or 256 bits.
1
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1answer
365 views
Most effect way to brute force 16 char AES key
I have a file that is encrypted in AES using a 16 char string. The string is (a-zA-Z0-9) and .,?!. It also only contains words from a dictionary (but they can be lower/upper case). What would be the ...
1
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3answers
205 views
Does the MixColumns step come before or after AddRoundKey in AES decryption?
I found these images depicting the AES decryption process:
In the first image, the MixColumns step comes before the AddRoundKey step, while in the second image, the AddRoundKey will come before ...
1
vote
1answer
818 views
Is AES restricted to only 64 characters for the key/password?
I am wondering if AES only supports 64 character passwords?
When using truecrypt, the maximum character limit on passwords is 64 characters; however, when using WinRAR, the limit is 128 characters.
...
1
vote
0answers
122 views
Calculating PGP Symmetrically Encrypted Packet data
I have been trying to create a properly encrypted data packet using the format described in RFC 4880. However, I have been unable to verify any of my outputs due to the lack of examples to draw from ...
1
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1answer
158 views
AES AddRoundKey
Looking at the first step of AES encryption I see that we XOR the key with the plaintext block. Why is the actual key involved at all, why not just use the round keys derived from the key schedule?
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2answers
170 views
Deriving HMAC key and cipher key from passphrase? [duplicate]
I'm encrypting a file with AES-256 in CBC mode. I needed to add an HMAC for authentication and validation of the file contents and passphrase, so I used a SHA-256 HMAC over chunks of my file ...
0
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2answers
170 views
What's the difference between AES and earlier block ciphers?
Is there any difference except speed and key and block size from user's point of view?
Or does AES have something that ideal block cipher doesn't have?
0
votes
1answer
180 views
What is the probability of breaking the AES algorithm?
I am doing a project which requires the encryption to be done using AES. Is it really possible (technically) to crack AES?
If yes, please tell me:
What is the probability of breaking AES?
How ...
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2answers
102 views
Generate fixed length cipher text from arbitrary length plaintext
Using an encryption algorithm like AES, is it possible to generate a fixed length cipher text no matter how long the plain text becomes?
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2answers
102 views
Is this how padding can work?
So for block ciphers you need a fixed size block.
If the plaintext length is not a multiple of the block length then you need to pad it.
One way you could do this is that for the last block you just ...
0
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2answers
305 views
decrypt AES without whole key
Is there a way to decrypt a AES cipher Text which was encrypted twice with some key, when having a part of this key? (the last 3 bytes of the key are missing)
0
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1answer
75 views
AES 128bit round level recommendation
we don't want change standard just after every attack, now for AES 128bit blocks i think 16 round is secure, but what is best round amount ? we had attack for 7 round then 10 round and it going so on ...
0
votes
1answer
407 views
AES key length greater than 256 bits - is it dangerous to do an implementation outside of the standard?
I'm making a digital-asset manager written in ActionScript 3, it will be used to manage highly sensitive information. I'm using the AS3Crypto library (which has quite a good reputation) to implement ...
0
votes
1answer
378 views
AES GCM symmetric encryption of data at rest in c#, ciphertext much longer than plaintext
I've written encryption/decryption routines using AES GCM. Code can be found here.
I recently realized that the cipher text is longer than I believe it should be. It should add the tag and IV onto ...
0
votes
1answer
784 views
Counter Mode in Advanced Encryption Standard(AES) Algorithm
In Advanced Encryption Standard, If I used "Counter Mode", in it's nonce value, what should I do?
ex. should I divide the nonce value into two? ex. I have 128-bit of nonce, should I divide it from ...
0
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2answers
85 views
The security of the AES secret itself
I am writing an application, running on a server, where multiple users access data from a database which is AES encrypted with a master secret. The master secret itself is initially randomly ...
0
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1answer
99 views
brute force attack on KDF vs KEY
if we believe 256bit keys are secure in AES against any brute force attack, is that possible we use a KDF (convert user's weak entered password in truecrypt into a fixed AES key) with too much round ...
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1answer
241 views
0
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2answers
172 views
AES key expansion vs. a hash
Is there something special about the AES key expansion algorithm that makes it secure, or it is a compromise between security and speed? For example, say with a key I expand it by taking pbkdf2(key) ...
0
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2answers
182 views
How can I add more rounds to AES?
I'd like to understand a bit more about the AES key schedule if anyone would mind explaining that. For instance, why is the way the schedule generated (with recursive xors and occasional ...
0
votes
1answer
439 views
Removing Padded Value in Decrypted Message
How to remove padded value in Decrypted Message?
I am using AES Algorithm..
ex:
this is the decrypted message..
"abcdefghijklmn "
there is a 2 space in that decrypted message which is equivalent ...
0
votes
1answer
1k views
How does one implement the Inverse of AES' MixColumns
I got an answer in the related question about Mixcolumn for encryption, but how about decryption?
what will I do?
Because it said that I will used this:
During decryption the Mix Column the ...
0
votes
1answer
175 views
Is AES reducible to an NP-complete problem?
Is breaking AES NP-hard? Can the security of AES be reduced to a NP-complete problem?
If it is reducible, what does the reduction look like?
If it is not reducible, why do we assume it is secure?
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votes
1answer
110 views
AES CBC with fixed or predictable IV, what are the risks?
I am making a call with parameters from application "A" to a web application "B".
Parameters are in the query string of the URL. They don't need to be hidden.
But I want to be sure that nobody can ...
0
votes
1answer
135 views
Design criteria for AES
I hope somebody can help me understand the design criterias for AES. Therefore, I would be really thankful if somebody could explain "non-linearity" in this context.
A criteria for the s-box in AES ...
0
votes
1answer
86 views
Using “Additional Authenticated Data” as a secondary key
In implementing a cipher in GCM or CCM mode, you are provided the option to add "Additional Authenticated Data" (AAD). This AAD is required for decrypting the cipher text, and seems to be used when ...
0
votes
3answers
266 views
AES-GCM and its IV/nonce value
I was reading about the differences between the GCM and the CBC more here and I have a follow up doubt on the same.
In the CBC mode the person who performs the encryption is the one who provides the ...
0
votes
1answer
154 views
AES Secure key generation and storage
I have a client-server application, which is transferring data between its components in a secure way. I currently use AES algorithm with CBC mode to transfer data and file. This is the scenario: ...
0
votes
1answer
212 views
Blowfish: hex digits of pi used for s-boxes?
Preface: here is the official site for the Blowfish algorithm:
http://www.schneier.com/blowfish.html
The Blowfish algorithm uses an s-box, which consists of hex digits of pi (found here: ...
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votes
2answers
98 views
Distinguishing Encryption Methods from the Output
Suppose that you see all IP communication packets between two computers for a day, as they pass through a connecting router, and this amounts to 10MB. You additionally know that all data transmission ...
0
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0answers
96 views
How secure is this perl script to use an AES encryption on files? [closed]
I am not entierly sure if it is appropriate to ask such a question here, but then again, I don't know a better place. If it is the wrong place, let me know, and I will remove it.
Could someone share ...
0
votes
1answer
223 views
How to break AES CBC with PKCS#5 padding?
If I have a string encoded with AES CBC with PKCS#5 padding, how can one possibly decrypt/crack it? What are the approaches that one can take to break its security?
0
votes
0answers
39 views
Security of .net AES implementation and security of a hash MAC
Hello I wanted to ask if there is any review about the security of the AES implementation of the .net Framework?
I found nothing concrete to that question, searching the Internet.
And, but this is a ...
0
votes
0answers
39 views
NIST Standard for Advanced Encryption Standard Algorithm [duplicate]
Possible Duplicate:
Advantage of AES(Rijndael) over Twofish and Serpent
What is the reason of NIST why Rijndael choose as the Advanced Encryption Standard
0
votes
1answer
209 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 ...
0
votes
0answers
46 views
Elliptic curve Cryptography [duplicate]
Possible Duplicate:
Can we use elliptic curve cryptography in wireless sensors?
How to map message character to point lies on Elliptic Curve? how to ecc used in wireless sensor networks? ...
-1
votes
2answers
283 views
Double Encrypting with two different keys
In terms of security, would it be MORE or LESS secure to take, say, an RC4 output (or Serpent) or other, that is encrypted with one key, and to encrypt that output with AES (using a different key)?
...
-1
votes
2answers
144 views
Is the AES encryption scheme CPA secure?
Give a 256 bit key space and 128 message space would AES block cipher as the encryption scheme be CPA secure?
-1
votes
1answer
89 views
What is the complexity of the Square attack against the reduced 4-rounds 128-bit Rijndael variant?
I'm looking at a square attack against a reduced version of AES-128 with only 4 rounds (with block and key size of each 128 bit). I have a set of 256 plaintext-ciphertext block pairs.
What is the ...
-1
votes
1answer
394 views
How to encrypt a File using AES Algorithm? [closed]
How to encrypt a file using private key in Java.
Adding this question, how to generate the private key for the same.
Before posting I went through some question like How to perform file encryption ...
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votes
3answers
119 views
how much is secure to encrypt a password using itself (as encryption key) for storing it on a unsecure media?
I want to store a password securely on a storage (suppose in a usual unencrypted file).
I use this password as AES key to encrypt itself (using AES-ECB) & then store it on the media (the password ...
-2
votes
2answers
222 views
Factoring a polynomial over a GF [closed]
I have the following question:
What polynomial, when factored over the field $GF (2^8)$ based on the irreducible polynomial that is used in Rijndael, will factor into all the polynomials in the ...
-2
votes
0answers
53 views
Is the likelihood of a birthday collision linear (evenly distributed) for all ciphers? When are they not?
When discussing the Birthday Principal, in combination with the pigeon hole principal, it was argued that an uneven distribution of birthdays (bias for September and any Tuesday of the year) made ...
-2
votes
1answer
99 views
What encryption is this? [closed]
uwwmXzKSP0M7DHBHns3v2CtNZh0TOicb
uwwmXH6KGgVLjpnoWCk9I2A+
uwwmcv7JoND9WE6xwaXdN6fLXaecRPqf+m6WmqE
uwAm5NXph0c9hkFK
are originally:
001bboc@explorer.csc.com
001bocaj@gmail.com
...
-2
votes
2answers
87 views
Is triple des similiar to RSA in that they message size is limited to the key size?
Is triple des similiar to rsa in that the message size you can encrypt is limited (unlike AES)?
Yes you can break the message size into parts and apply it, but I'm not interested in doing that so I ...
-3
votes
1answer
114 views
AES implementation in java that allows key of 320-bit length [closed]
I need an implementation of AES(Rijndael) in java that allows use of a 320-bit key.
Please suggest a reliable implementation
-3
votes
1answer
433 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 ...
