Flaws found in Canon Image Verification System
Encryption expert Dmitry Sklyarov--who was previously arrested (and acquitted) by the FBI after cracking the encryption used in Adobe System's eBook format--has made the headlines again. This time, Sklyarov demonstrated how his company, Elcomsoft, has found and successfully exploited a vulnerability in Canon's OSK-E3 system, a feature found in mid to high-end cameras made by the company.
In essence, the OSK-E3 cryptographic system was invented as a way to verify that digital photos have not been retouched, and that crucial metadata such as timestamps or GPS coordinates have not been changed. It can be used to ensure that photos taken by police for evidence gathering, for example, have not been tampered with; organizations such as The Associated Press also use it to verify the authenticity of photos taken by its reporters.
Elcomsoft was able to break the system by extracting the secret code used to create the verification data from the internal memory of different Canon camera models. The code is apparently the same across each model of camera; the company told PC World that it has extracted the keys for the EOS 20D, EOS 5D, EOS 30D, EOS 40D, EOS 450D, EOS 1000D, EOS 50D, EOS 5D Mark II, EOS 500D and EOS 7D to date.
From my perspective, Canon should have implemented a dedicated cryptographic chip that performs the necessary computation of verification data--separate from the main operations of the camera. For now, Elcomsoft has released a number of doctored photos to prove its point.