What type of attack involves trying all possible keys to decrypt data?

A brute force attack is an exhaustive method of decrypting data by systematically trying every possible key until the correct one is found. This approach relies on the computational power available to the attacker, aiming to guess the key in a trial-and-error fashion. Since encryption algorithms often involve a vast number of potential keys, brute force attacks can take an impractically long time to execute if strong encryption is used.

In contrast, a dictionary attack uses a predefined list of likely passwords or keys (the "dictionary") to guess the correct one, which is generally much more efficient than a brute force approach but only works effectively against weak security. Phishing attacks focus on tricking individuals into revealing confidential information rather than attempting to crack encrypted data, and denial of service attacks focus on overwhelming a system rather than decrypting it. Therefore, in the context of trying all possible keys for decryption, a brute force attack is the accurate term.