TrueCrypt remains the only way to encrypt Amazon Simple Storage Service (S3) data when using the AWS Import/Export tool, two weeks after the popular encryption software was abruptly discontinued by its creators, supposedly for security reasons.

According to Amazon Web Services (AWS) online documentation, "TrueCrypt is the only device encryption supported by AWS Import/Export." On a separate page about AWS security, Amazon says that: "AWS only ships devices out of AWS facilities if the device is completely erased or the device only contains data encrypted by AWS. For import jobs, we erase devices after job completion. For export jobs, we will always encrypt the data being exported onto the device. We use TrueCrypt software for encryption."

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The authors of TrueCrypt, whose identities remain unknown, ended the project on May 28 with a sudden message warning users that "using TrueCrypt is not secure as it may contain unfixed security issues." The project's home page advised users to switch to encryption technologies integrated directly into modern operating systems like BitLocker Drive Encryption in recent versions of Windows or FileVault in Mac OS X.

TrueCrypt version 7.2, which can only be used to decrypt data, was released at the same time as the announcement about the end of the project, and all previous versions that included encryption functionality were removed from the project's repository.

The authenticity of the announcement has been questioned by some users and several possibilities were advanced, including that it was fake and posted by hackers or that the authors were identified by a government and forced to shut the project down.

The Open Crypto Audit Project (OCAP), a community initiative that was in the process of analyzing the security of TrueCrypt when its development was discontinued, set up a repository this week with verified builds and source code for TrueCrypt 7.1a, the last version of the software to include encryption.

OCAP plans to complete its TrueCrypt audit, which is now in phase two and involves analyzing the software's cryptographic functions. The first phase, which involved searching for vulnerabilities in the program's critical components like its Windows kernel code, the bootloader and the filesystem driver was completed in April with no critical issues being identified.

Amazon.com did not immediately respond to an inquiry seeking information on whether it plans to support other data encryption technologies for the AWS import/export feature aside from TrueCrypt in the future.