[$] A comparison of cryptographic keycards

An earlier LWN article showed thatprivate key storage is an importantproblem to solve in any cryptographic system and established keycardsas a good way to store private key material offline. But which keycardshould we use? This article examines the form factor, openness, andperformance of four keycards to try to help readers choose the one thatwill fit their needs.