One early steganographic program was written by a hacker who had once posed for Playboy. Searching so far has only produced references to Playboy images used for steganographic test images (most famously, the Bebe Buell Playmate of the Month centerfold).
I’m sure I saw this information back in the 1990s. In light of the Russian spys using it, I want Rachel Maddow to do one of her “Moments of Geek” on Steganography, and was trying to find the name of this person to give the subject a compelling “angle”.
Her most recent show quoted some “expert” that this was the “first use of Steganography” - which is bullshit. I used an Amiga steganography program to make a password for an FTP site available, posting it in an image hosted on that server with a hint to the ID of the photo posted on a Usenet newsgroup.
NPR just had an expert on the radio talking about it but I wasn’t interested enough to absorb it. He did mention a website to download from steganography.com, I guess. Doesn’t interest me enough to check. What was the question in the OP?
I’d not be entirely convinced that steganography is any younger than cryptography. They’re both obviously ancient. Even the nuanced literature on the history of the latter becomes an account of “secret writing” in general when discussing that far back.
Forestalling any pedants, I should acknowledge that cryptography does literally mean “secret writing”. My point however is that through the 20th century the term cryptography tended to contemporaneously mean codes and ciphers, not steganography. The likes of Enigma and Venona are thus, for example, what springs to mind when one refers to 20th century cryptography.
The interesting thing about steganography, especially in re Russian spies, if that you can hide information in plain sight, encoded into the least significant bits of an image uploaded to a web site, as opposed to traditional cryptography where someone can tell that the item is encrypted.