Collaborate Disseminate
Consider an application that runs locally on a Windows PC. The application uses a local folder for reading/storing encrypted data (i.e. images). A user logs in (authenticated from a local encrypted DB). The application needs … Continue reading Is it secure to store a cryptographic key in a class member variable?
AFAIK both Microsoft Office and LibreOffice have features to add passwords to protect the content.
In general, there are two ways:
protect from editing/changing (without a revision at least)
protect from opening (without p… Continue reading How secure is Microsoft’s Office and LibreOffice’s password protection?
We have a requirement from customer to write payment transaction information to a text file. Of many lines of data per transaction, only one line contains cardholder information, which needs encryption to be PCI-Compliant.
M… Continue reading Can we write both encrypted text and plain text to the same file?
The operating mode of an encryption algorithm, especially a block
cipher, describes how to use the encryption function for a single
block repeatedly to encrypt or decrypt an entire messages with a
single key.
I’ve … Continue reading operation mode of an encryption algorithm
I’ve read some articles and tutorials about AES GCM and was using this cipher for one of my java-projects, so let’s say I know some basics.
I read that you should use an IV-length of 12 bytes which means that there should b… Continue reading how much is AES GCM’s security affected when not using unique IV’s
A popular zero-knowledge file sharing site uses a 128-bit master key for encryption.
However, they claim to be using AES256. When questioned, they explained the master key is widened using PBKDF2 and random salt to 256-bits… Continue reading AES256 with 128 bit key
If we agree that using a null IV for AES in CBC and GCM mode is not a good idea, but for whatever reason one is encouraged to use a null vector for several messages using the same key, is there a “least worst” option between … Continue reading Null IV for AES CBC vs GCM
If I do not understand wrong from this post and Wikipedia page of the BitLocker and TPM, by default, BitLocker uses symmetric cryptography like AES. However, TPM is capable of performing RSA encryption.
Given that, the RSA ke… Continue reading Why does BitLocker not use RSA?
I encrypted a file by using the following command from a stackoverflow answer:
openssl enc -in file_name -aes-256-cbc -pass stdin -out file_name.aes;
I can decrypt this file by running:
openssl enc -in file_name.aes -d -a… Continue reading Cross platform OpenSSL aes encryption
I’m currently investigating a piece of software which encrypts it’s files with AES-128-CBC.
From disassembly it is truly known that the algorithm used is correct (log messages plus calls to the BCrypt library).
The key and… Continue reading Decrypting AES-128-CBC leads to first block being correct, the rest corrupt