key
鍵 centers on a physical key used to lock or unlock something. It can also refer to a crucial element that provides access or understanding, like a key to a puzzle.
鍵 combines 金 (metal) with 建, which likely contributes the sound and the idea of setting up or establishing, suggesting a metal device that secures or establishes closure.
The left side is metal 金, and the right side 建 looks like a person setting up a lock. Picture a metal key being inserted to set the lock in place.
For ケン, imagine a key shaped like the letter 'K' that you can use to open a can: K-can -> ケン. The metal key unlocks the can.
key
keyboard (of a piano, typewriter, etc.)
duplicate key
locksmith
keystroke
keyhole
public key
Public Key Infrastructure
public key encryption
public key cryptosystem
shared key
symmetric key cryptography
shared key encryption
symmetric key cryptography
internal lock
to have the game in one's hands; to hold the key to victory
symmetric key cryptography
key success factor; key to success; KSF
encryption key
cryptographic key; encryption key