I have issue with the transactions period, 5 seconds seems to fast for me, I read somewhere that there is positive correlation between security and transaction time, so 5 seconds seems to expose the coin to attack, correct me if I am wrong
That is true for a proof-of-work blockchain. It is not true for other types of blockchains such as proof-of-stake and permissioned witnesses.
A proof-of-work blockchain depends on computations for security, and as time passes, more computations can be performed, so the security margin increases. It is not the blockrate that matters though, it is the amount of time the recipient waits before accepting a transaction, and that is determined by the recipient herself, not the blockchain. So for example, bitcoin has a proof-of-work blockchain and it is generally recommended that a recipient wait at least an hour (6 confirmation) before accepting an important payment, and for really important payments, the recipient should wait 24 hours. If the bitcoin target block rate were doubled or cut in half, you would still need to wait the same amount of time, 1 hour or 24 hours etc., to achieve the same security margin. So even with proof-of-work blockchains, ignore the blockrate and focus on the wait needed for all miners to perform N hash computations, which doesn't depend on the blockrate. Note however that security is never guaranteed with a proof-of-work blockchain; it is only probabilistic and subject to certain assumptions such as the inability of an attacker to co-opt a significant portion of the hash power (sometimes assumed to be less than 10%, sometimes less than 50%, or sometimes something in between, depending on the analysis and assumptions). Proof-of-work currencies with low hash power, or that have hash power concentrated into mining pools that could potentially be compromised or co-opted, will be less secure and will require a longer wait time than a proof-of-work currency that has a high hash rate running outside mining pools and distributed among many participants.
We're not convinced any new currency that uses proof-of-work can be secure, since the hash power will be relatively low. This has been demonstrated recently in some new proof-of-work currencies that have been successfully attacked.
CredaCash does not use proof-of-work. For speed and security, CredaCash currently uses permissioned witnesses and will migrate to unpermissioned proof-of-stake. In addition however, and most significantly, CredaCash introduces the concept of cleared or final transactions. After a majority of the witnesses have signed off on a block twice, that block is considered permanent or as we call it in our documentation, "indelible". A transaction in an indelible block is guaranteed by the protocol to be permanent, and the software reports these transactions as cleared. That takes roughly 5 to 10 seconds, and once a transaction has cleared, it is permanent. If the witnesses, whether permissioned or proof-of-stake, attempted to replace or revert an indelible block or a cleared transaction, that would be rejected by all of the other nodes in the system. The security of CredaCash then comes from all of the nodes in the system working to reject transactions and blocks that violate the protocol.
Bitcoin and other proof-of-work currencies do not have a similar technology--in those currencies, a block is never final or permanent, and is subject to being replaced at any time if some miner can produce a higher cumulative proof-of-work. That is where the recommendation to wait 1 to 24 hours comes from, and even then, there is no guarantee.
