steganography
noun
steg·a·nog·ra·phy ˌste-gə-ˈnä-grə-fē 
1
archaic : cryptography
2
: the art or practice of concealing a message, image, or file within another message, image, or file
steganographic
ˌste-gə-nə-ˈgra-fik
adjective 
Did you know?
Steganography is a word that was resurrected after being in disuse for almost 150 years! It was put to rest in the early 1800s, labeled an archaic synonym of "cryptography" by dictionary makers, but was brought back to life in the 1980s as a word for a type of digital cryptography. There is nothing cryptic about the word's origin; it is based on the Greek word steganos, meaning "covered" or "reticent."
Example Sentences
Recent Examples on the Web Fileless, living-off-the-land attacks that use steganography to encrypt and hide many types of malicious software, including video files. 
Chuck Brooks, Forbes, 9 May 2021 After getting a call from a man named Belsky who's an expert in Cold-War-era steganography, Reddington shows Cooper a photo of a billboard. Jodi Walker, EW.com, 1 May 2021 The PowerShell script reaches out to either imgur.com or imgbox.com and downloads an image that has malicious code hidden inside the pixels through a technique called steganography. Dan Goodin, Ars Technica, 30 May 2020 Mallory explained in interviews with the CIA and FBI that were played in court on Thursday that the phone contained an app designed to facilitate steganography, or the hiding of information inside of an image. Rachel Weiner, Washington Post, 1 June 2018 Provos has been working on steganography since June, ever since USA Today printed a sensationalistic report, which called encryption one of bin Laden's favorite tools. Farhad Manjoo, WIRED, 8 Nov. 2001
Chuck Brooks, Forbes, 9 May 2021 After getting a call from a man named Belsky who's an expert in Cold-War-era steganography, Reddington shows Cooper a photo of a billboard. Jodi Walker, EW.com, 1 May 2021 The PowerShell script reaches out to either imgur.com or imgbox.com and downloads an image that has malicious code hidden inside the pixels through a technique called steganography. Dan Goodin, Ars Technica, 30 May 2020 Mallory explained in interviews with the CIA and FBI that were played in court on Thursday that the phone contained an app designed to facilitate steganography, or the hiding of information inside of an image. Rachel Weiner, Washington Post, 1 June 2018 Provos has been working on steganography since June, ever since USA Today printed a sensationalistic report, which called encryption one of bin Laden's favorite tools. Farhad Manjoo, WIRED, 8 Nov. 2001 Word History
Etymology
New Latin steganographia, from Greek steganos covered, reticent (from stegein to cover) + Latin -graphia -graphy — more at thatch
First Known Use
1985, in the meaning defined at sense 1