Learn in the textbookFundamentals of Encryption and Cipher Methods
DefinitionHybrid cryptography (ハイブリッド暗号方式) encrypts the message with symmetric-key cryptography (共通鍵暗号方式), encrypts that shared key with the receiver's public key, and sends the two together.
ExplanationIt combines the speed of symmetric-key cryptography with the easy key handover of public-key cryptography. The slow public-key calculation is needed only for the short shared key, while the bulky message is handled by the fast shared key. Encrypted web traffic (SSL/TLS) is one place it is used.
AnalogyIt is like shipping your belongings in an ordinary locked trunk and enclosing only the trunk key in a small box fastened with the recipient's padlock.
Memory hookJust as a hybrid car switches between its engine and motor depending on the situation, this scheme gives each of the two methods its own job.