Ever considered to use the encryption software included with some data medium, like SanDisk SecureAccess or similar (Lexar, Sony or Western Digital)? At least some of them offer AES 1024bit encryption, marketed as "military grade".
As exposed by Sylvain Pelissier, it was not only a marketing gag (as AES is specified for keys only up to 256bits), but also a security failure (as it gave a real security equivalent to 128bits).
Link to rC3 - will update as soon as the recording gets published.
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