How can read the data field in a transaction?

Question

if im sending a transaction including a hex data, who can read it? Is it encrypted and only the receiver can read it? If not, everyone can read the data...

Answer 1

Anyone can read it. The entire blockchain is public.

Answer 2

https://api-rinkeby.etherscan.io/api?module=proxy&action=eth_getTransactionByHash&txhash=HASH&apikey=YourApiKeyToken

response's input field is the corresponding hex data.