This paper demonstrates how to exploit the encrypted key import functions of a variety of different cryptographic devices to reveal the imported key. The attacks are padding oracle attacks, where error messages resulting from incorrectly padded plaintexts are used as a side channel. This is the paper that made headlines regarding RSA tokens being cracked in 13 minutes.
You can download it from the following link: https://packetstormsecurity.com/files/download/114229/RR-7944.pdf
Source: https://packetstormsecurity.com/files/114229/Efficient-Padding-Oracle-Attacks-On-Cryptographic-Hardware.html