Encryption Flaw in "secret.pdf.enc1": Decrypting a PDF File with Cryptanalysis
How can the key of the encrypted file "secret.pdf.enc1" be disclosed?
The encryption algorithm used in the file "secret.pdf.enc1" is a flawed XOR encryption. By knowing the first eight bytes of the plain text and cipher text, the key can be disclosed, allowing for decryption of the pdf file using cryptanalysis.
The Key Disclosure in XOR Encryption Algorithm
The encryption algorithm used in the file "secret.pdf.enc1" is a simple XOR encryption. The algorithm reads the pdf file eight bytes at a time, and each eight bytes are XORed with a stream generated by the key. The flaw in the encryption algorithm is that if the first eight bytes of both the plain text and the cipher text are known, the key can be disclosed. In this case, as the plain text of the first eight bytes of a pdf file can be obtained from the PDF specification, this information can be used to find the key and decrypt the pdf file using cryptanalysis.
Decrypting "secret.pdf.enc1"
To decrypt "secret.pdf.enc1" via cryptanalysis, one can leverage the flaw in the XOR encryption algorithm. By obtaining the first eight bytes of both the plain text and the cipher text, the key can be deduced, leading to successful decryption of the entire PDF file.
Understanding Encryption Flaw in "secret.pdf.enc1"
The encryption algorithm used in the file "secret.pdf.enc1" employs a simple XOR encryption method. This method reads the pdf file in blocks of eight bytes and XORs each block with a key-generated stream. However, a critical flaw exists in this algorithm where knowledge of the first eight bytes of both the original text and the encrypted text can reveal the encryption key.
By exploiting this vulnerability, individuals can decrypt "secret.pdf.enc1" through cryptanalysis. This process involves utilizing the known bytes to infer the key and subsequently decrypt the entire PDF file. Cryptanalysis allows for breaking the encryption scheme and accessing the contents of the encrypted document.
Understanding encryption flaws and vulnerabilities is crucial in ensuring secure data transmission and storage. By analyzing weaknesses in encryption algorithms, security professionals can enhance data protection mechanisms and prevent unauthorized access to sensitive information.