Users who perform Bitcoin transactions have a public address. These addresses are about 30 characters long and usually begin with 1 or 3. Any address used in any transaction can be seen by anyone. Bitcoin is defined as an "anonymous currency" because these addresses are difficult to remember without a computer and do not contain any personal information.
However, this is not as simple as it seems. If you share your address anywhere, that address can be matched to your real identity. Also, even if you do not share your address anywhere, using the same address for many transactions can enable a skilled analyst to link the address to your identity by looking at transaction times, quantities, locations and patterns. This method is used in Mt. It has been used to investigate the theft of companies such as Gox and Bitcoinica. But potentially its intended use is to identify anyone. In order to raise privacy and security to a higher level, care should be taken to use a new address for each transaction.