"Cryptography is the science of hiding information through ciphers and codes. Cryptographers devise new cryptographic algorithms." (Michael Coles & Rodney Landrum, , "Expert SQL Server 2008 Encryption", 2008)
"The process of converting data into an unreadable form via an encryption algorithm. Cryptography enables information to be sent across communication networks that are assumed to be insecure, without losing confidentiality or the integrity of the information being sent." (Alex Berson & Lawrence Dubov, "Master Data Management and Data Governance", 2010)
"The science (or art) of providing secrecy, integrity, and non-repudiation for data." (Mark S Merkow & Lakshmikanth Raghavan, "Secure and Resilient Software Development", 2010)
"The art or science of rendering plain information unintelligible, and for restoring encrypted information to intelligible form." (Manish Agrawal, "Information Security and IT Risk Management", 2014)
"Science of secret writing that enables an entity to store and transmit data in a form that is available only to the intended individuals." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)
"The encoding of data so that it can be decoded only by certain persons. The role of cryptography is to protect data integrity, confidentiality, nonrepudiation, and authentication." (Mike Harwood, "Internet Security: How to Defend Against Attackers on the Web" 2nd Ed., 2015)
"The field of study related to encoded information" (Nell Dale & John Lewis, "Computer Science Illuminated" 6th Ed., 2015)
"The science of secret writing that enables storage and transmission of data in a form that is available only to the intended individuals." (Shon Harris & Fernando Maymi, "CISSP All-in-One Exam Guide" 8th Ed., 2018)
"The study of algorithmic transformations from plain text to encrypted forms in which the unencrypted data cannot be ascertained without possession of the encryption key." (O Sami Saydjari, "Engineering Trustworthy Systems: Get Cybersecurity Design Right the First Time", 2018)
"A technique to secure communication or data." (AICPA)
"Art or science concerning the principles, means, and methods for rendering plain information unintelligible and for restoring encrypted information to intelligible form."(CNSSI 4009-2015 NSA/CSS)
"The art and science of using mathematics to secure information and create a high degree of trust in the electronic realm." (NISTIR 7316)
"The discipline that embodies principles, means and methods for providing information security, including confidentiality, data integrity, non-repudiation, and authenticity." (NISTIR 8040)
"The discipline that embodies the principles, means, and methods for the transformation of data in order to hide their semantic content, prevent their unauthorized use, or prevent their undetected modification." (NIST SP 800-59)