The padding-oracle tag has no wiki summary.
3
votes
2answers
151 views
Using the same secret key for encryption and authentication in a Encrypt-then-MAC scheme
Is it a weakness to use a single shared secret for protecting messages using a Encrypt-then-MAC scheme?
Assuming a system is using AES-256-CBC and a SHA1-HMAC and the same secret key for both ...
2
votes
1answer
179 views
Extract private RSA key from USB cryptographic token using Bardou et al. attack (varian of “million message attack”)
There is a side channel attack on tamper-resistant USB cryptographic tokens using padding-oracle, described by Bardou, Focardi, Kawamoto, Simionato, Steel and Tsay, titled "Efficient padding oracle ...
3
votes
1answer
77 views
How to use HMAC for large ciphertexts over TLS
HMAC used to secure chosen cipher-text attacks. if we are encrypting a large file (video) and sending it over TLS for decryption, how server can check MAC for ciphertext when we didn't sent whole of ...
1
vote
1answer
84 views
Understanding padding oracles - is an attack plausible in my scenario?
I have a scheme that, long story short, uses AES in CBC mode to encrypt third-party credentials for user accounts with a password-derived key. It's been mentioned that the use of CBC mode is a ...
1
vote
2answers
104 views
What is an easy method of proving that a cryptographic oracle attack is possible?
Lets say an application is using CBC mode without authentication. The application is generating cipher text. This cipher text can be manipulated by the attacker and then transmitted back to the ...
4
votes
2answers
1k views
How does a padding oracle attack work?
I am unsure of how a padding oracle attack works.
What I am not getting is how changing one bit at one time allows one to exploit(get keys) ASP.NET machines.
Can anyone explain this?
2
votes
1answer
265 views
Shortcuts / practicality of brute forcing block cipher (AES) + ECB with known plaintext
I know the plaintext (26 bytes long) and cryptotext of block cipher (suspected to be AES) in ECB mode. I can generate hundreds or thousands of such samples, but the samples are not arbitrary. What are ...