Side-channel analysis (SCA) is a powerful tool to extract (cryptographic) secrets by observing physical properties (power consumption, EM) of a target device. After an intro to SCA and related methods, the speaker will demonstrate the practical relevance of SCA with two case studies: first, how SCA can be used to circumvent the IP protection (bitstream encryption) of FPGAs. In a similar way, AES keys of one-time password tokens can be extracted, allowing an attacker to steal digital identities.