If you've tried adding a new token to your wallet, one thing you will have noticed is the field asking for a Token Contract Address. This refers to the address location of the actual token contract that manages the logic for the tokens. It does not refer to the address that holds your own personal tokens!
What's the difference between a contract and an address?
The addresses just provide a key into the state trie, so they act in the same way and should be considered the same. The main difference is that the account data structure for a contract contains an entry for codehash, meaning there's some executable code that can be run. For an externally owned account, there's just a balance and nonce.
How do I encrypt a contract address?
Like above, contract address can be achieved by sender's nonce and sender's address. 1) encode sender's address and sender's nonce with rlp. 2) hash it with keccak256. 3) slice right most 20 bytes (40 words). 4) Add a '0x prefix.
