Although Oraclize is a trusted service, you may still want to check whether the data returned by Oraclize is authentic or not, that is, whether it was manipulated by Oraclize or someone else in transit.
Optionally, Oraclize provides the TLSNotary proof of result that's returned from the URL, blockchain, and nested and computation data sources. This proof is not available for WolframAlpha and IPFS data sources. Currently, Oraclize only supports the TLSNotary proof, but in the future, they may support some other ways to authenticate. Currently, the TLSNotary proof needs to be validated manually, but Oraclize is already working on on-chain proof verification; that is, your smart contract code can verify the TLSNotary proof ...
