Symmetric Key Cryptography necessitates distributing the key to all participants.
Symmetric Key Cryptography allows all parties must trust each other, because they can read each other's messages.
Physical distribution of symmetric keys is the safest because an unencrypted electronic transmission of a key would be vulnerable to theft. Physical key distribution would make symmetric keys hard to use in an environment with a large number of users. Even with Physical distribution, the keys are still vulnerable to theft.
However, often some application uses a clever combination of encryption schemes to distribute symmetric keys over the network for background authentication.
Symmetric Key Cryptography LDAPWiki refers you to Wikipedia: Symmetric-key_algorithm
Symmetric Key Cryptography Cryptographic Algorithms (sometimes known as secret-key algorithms) transform data in a way that is fundamentally difficult to undo without knowledge of a secret key. The key is symmetric because the same key is used for a encryption and decryption).
Symmetric keys are often known by more than one entity; however, the key shall not be disclosed to entities that are not authorized access to the data protected by that algorithm and secret-key. Symmetric Key Cryptography algorithms are used, for example,