Sendcrypto - Audit

In the contract `SendCryptoToken` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority and mint tokens to any address  In the contract `SendCryptoStaking` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority - sets the state accepting staking of being stopped through `setStopped()` - sets the state staking compounding of being stopped through `stopCompounding()`  In the contract `SendCryptoLocking` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority and allow setting package information.  In the contract `SendCryptoLiquid` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority and allow setting package information. 

`SendCryptoToken`, `SendCryptoLiquid` and `SendCryptoLocking` are upgradeable contracts, the owner can upgrade the contract without the community's commitment. If an attacker compromises the account, he can change the implementation of the contract and drain tokens from the contract.

Total amount of `235000000 * 10 ** 18` tokens were sent to the `msg.sender` when deploying the contract. This could be a centralization risk as the deployer can distribute tokens without obtaining the consensus of the community.

When transferring standard ERC20 deflationary tokens, the input amount may not be equal to the received amount due to the charged transaction fee. As a result, an inconsistency in the amount will occur and the transaction may fail due to the validation checks.