Encryption has traditionally been difficult and expensive to use. This reputation was often well deserved. The 1999 study by Alma Whitten and. J. D. Tygar at Carnegie-Mellon University,
The element that made encryption difficult and expensive was managing cryptographic keys, the data that lets you encrypt and decrypt information. Managing keys was simply too hard for both users and administrators, and these difficulties led to higher costs for training and support, and prevented the technology from being widely adopted.

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