hayazushi (type of sushi with vinegared fish and rice lightly pressed overnight)

oshizushi (soft-pressed sushi topped with ingredients)

narezushi (old-style fermented sushi (pickled in brine rather than vinegar)

funazushi, a type of narezushi (traditional fermented sushi) made from fish of the crucian carp genus (Carassius)

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.

(literally) sniff around / (figuratively) nose around, snoop