Timestamp Meaning

What is Blockchain-Based Timestamp?

A timestamp is used to keep a record of information on a computer or any other digital platform. For example, a timestamp in a digital camera represents the exact date and time when the photo was taken. 

In cryptocurrency, a timestamp shows the “Unix” time, or the time and date when a block was mined and validated by a blockchain network. Decentralized timestamps show the degree of difficulty and the time it took to mine the block.

Blockchain timestamps are protected by security rules. So, even if a Bitcoin miner tries to tamper with the timestamp by showing an incorrect time, they may not be able to do so.

When a block is created, it has two timestamps – the one marked on the block header by the miner and the actual time when the block was generated. Generally, these two timestamps must be the same but sometimes, a miner may try to lie about how much time it took to mine the block to increase their mining revenue. The faster they mine the block, the more revenue they get.

This is why blockchain timestamping is protected by two rules:

• The Median Pass Time (MPT) rule states that the timestamp must be higher than the median timestamps calculated for the previous 11 blocks. The miner should calculate the hashing time of the previous 6 blocks out of the 11 blocks.
• The “future block time” rule states that the timestamp must not be more than 90 minutes compared to the local time recorded in the miner’s computer.

Blockchain-based timestamping provides a digital signature and authenticates the time. Once a timestamp is published to a ledger it cannot be removed or tampered.