One may not have derived from the other yet Cephas is definitely associated with the English language as can be seen with the definition and use of the word Cephas as of or relating to the head.
The name Cephas does not have ties to the Greek for head. That word is "cephalus" and the word "cephalophore" is derived from that not Cephas. Cephas is not even Greek as mentioned previously but Aramaic.
IN MATTHEW 16:18 JESUS SAID And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. JESUS CALLED PETER OR PETROS OR CEPHAS A ROCK Πέτρος Pétros, pet'-ros; apparently a primary word; a (piece of) rock (larger than G3037); as a name, Petrus, an apostle:—Peter, rock. Compare G2786. AND HE LATER IN THE SAME PASSAGE CALLED HIMSELF πέτρα, πέτρας, ἡ, from Homer down; the Sept. For סֶלַע and צוּר; a rock, ledge, cliff; WHICH ALSO MEANS A MAN LIKE A ROCK. HE IS ALSO CALL A FIRM FOUNDATION 1 CORINTHIANS 3:11For no man can lay a foundation other than the one which is laid, which is Jesus Christ. ALSO EPHESIANS 2:20 having been built on the foundation of the apostles and prophets, Christ Jesus Himself being the corner stone, PROVES THAT JESUS IS THE FOUNDATION OF THE CHURCH AND THE FOUNDATION OF OUR SALVATION. HOW COULD GOD BUILD HIS CHURCH ON A SINNER AND A MAN SO MOVABLE SUCH AS PETER? THIS ROCK IS THE SAME MAN WHO DENIED CHRIST THREE TIMES AND HAD TO BE RESTORED AFTER THE RESURRECTION. JESUS IS THE PETRA AND THE FOUNDATION OF THE CHURCH.
Cephas is the Aramaic for the Hebrew name Silas which is the actual name Yeshua named Shimon bar Yonah. The word silah in Hebrew means rock. Yeshua understood and spoke Aramaic but it was not His daily language! Hebrew was in fact His daily language! It is a common misconception because of one line He spoke whilst on the cross, eloi, eloi, lama sabachthani which in Hebrew would be eli, eli, lama azavtani. The people around Him thought He was calling on Elijah because they could not understand Aramaic! For that reason alone we know that Yeshua did not name Shimon Cephas but rather Silas, the Hebrew version of the name Petros (Greek). There is a companion of the apostle Paul who was also named by this name and traveled with him as well as with a Judas Barsabas and later with Timothy. It is a common misconception that the name Silas was derived from the Latin as it became a popular name among the Romans because of Peter!
Messiah is the rock, and Kefa as well, as by his testimony, that Jesus of Nazareth is the Son of the Living God, and Messiah, was first spoken.
So yes, Kefa is a type of rock, or else Christ would not have named him such, recorded for us in both Aramaic, and Greek. As we are saved first by trusting in Christ, and then by following Him, through Kefa came not only a confession of faith, but later, written confirmation that Paul's letters are Scripture, surely as the Law, Prophets, and Psalms.
Bible students recognize the truth that the "rock" reference in Matthew 16:18 is a reference to Christ not to Peter. Study the two different Greek words used there. The New Testament Christian Church is built on Christ and his gospel, death, burial, and resurrection.