talisman

quotation marks

pictorial / graphic / painted / picture / painting / drawn / image / plan

New Age music

pull / tug / admit

key (tool for opening or locking something) / key; clue (important fact for solving something) / lock

(computing) key / (music) key

(cryptography) secret key

keyhole

(cryptography) key exchange - an exchange of peers' keys at initialization phase of connection.