Which software was the first to use copy protection?

Question

While researching early magnetic storage around 1980, I've come to ponder if we know of the first piece of software on removable media that employed copy protection?

The Wikipedia article mentions that copy protection schemes became important when software started to be distributed on floppy media rather than tape - yet there's no indication of which piece of software was first to use some sort of protection, if there were some efforts on tape media already, or similar pointers on when it actually started to become a common thing.

In regards to technologies employed, the article outlines that mostly custom loading mechanisms were chosen to prevent data from being easily copied. It would be interesting to trace early efforts, how they transformed and when - for example - off-media schemes like on-paper lookup tables or code wheels were introduced.

Update: This question has already gathered very interesting insights and widened the perspective of how broad the copy protection topic actually can be once you look beyond in-software schemes. So bonus points for pointing out an actual single piece of software per storage media, like "Game X shipped on tape first and used this scheme" or "Program Y came on 8-inch floppies and did that to prevent copies."

Answer 1

I couldn't say which one was the first but there were early efforts in the 1970's and 1980's

Encrypted roms

Arcade games were often hacked so ROM encryption was developed, so if the board was re-made with standard components and ROM dumps, it failed to work. Some special device decrypted the instructions on the fly between the CPU and the ROM.

For instance, you can check https://www.planetemu.net/rom/mame-roms/ckongcv which has encryption and is from 1982.

Protected tapes

Most games from the early 1980's came on tape. It took ages to load, and when you wanted to make a copy of a friend's program, you had to load, stop the program, and save the basic or/and memory to tape.

That was different for most commercial releases.

• Some tried to prevent you from stopping the program and getting the prompt back. No prompt no easy backup. Redirecting the basic prompt to a routine that crashed the machine was a common way of doing it.
• Some used document/manual protection already (there's the well-known ZX-spectrum lenslok system), so you could copy the tape but not the manual/wheel/whatever.
• Some sync signals were shortened to the max so the interesting program immediately started after an intro program and it was difficult to locate it.
• Custom tape formats were developed sometimes to speed up loading and prevent programs that used the standard way of reading the bytes from the tape to work.

Of course it was always possible to use a double tape deck to copy the tapes but it heavily depended on the quality of the tape deck (personally I never succeeded in pulling that off, plus you can't do that on the copy of the copy because of the analogue nature of the copy...)

All those tape protections were not that hard to workaround... Maybe the hardest ones were the document protections as you had to disassemble the game to understand it, and there weren't a lot of disassemblers let alone debuggers back in the day.

Final note: To provide more details, my personal experiences originate mostly from Oric Atmos where I "cracked" a lot of games with various techniques, but I also tried to crack/copy games when I briefly encountered a ZX Spectrum, without any experience besides the Oric one, and some attempts were successful, to my surprise. I called a cracked game a game which then can be copied by anyone with minimal skills (interrupt/warm reset a machine and dump to tape).

Answer 2

One of the earliest would likely have been Microchess 2.0 for the Apple II, shipped on cassette in 1978. Andy McFadden's Early Copy Protection on the Apple II article has the details.