Substitution Cipher Puzzle

The phrase "Stairway to Heaven" comes from the iconic song by the English rock band Led Zeppelin, released in 1971 on their untitled fourth studio album. Composed by guitarist Jimmy Page and vocalist Robert Plant, it is widely considered one of the greatest rock songs of all time. The lyrics, penned by Plant, are often interpreted as a poetic critique of materialism, with a central figure believing she can acquire a path to heaven through wealth. The song's distinct structure builds from a gentle acoustic opening, featuring John Paul Jones on recorder, to a powerful hard rock crescendo, culminating in Jimmy Page's legendary guitar solo. Despite its immense popularity and frequent radio play, the band famously never released it as a commercial single.

This puzzle employs a substitution cipher, a foundational method in the field of cryptography. A substitution cipher works by replacing each letter of the original message, known as the plaintext, with a different letter or symbol to obscure its meaning, creating what is called ciphertext. The history of cryptography stretches back thousands of years, with early forms of substitution evident in ancient Egypt around 1900 BCE, where scribes used non-standard hieroglyphs. A more widely recognized historical example is the Caesar cipher, attributed to Julius Caesar, who utilized a simple shift of letters in the alphabet to secure his military communications around 100 BCE. These ciphers have played a vital role in protecting secret messages throughout history.