What is SHA?
The term secure hash algorithm (SHA for short) refers to a group of standardized cryptological hash functions. These are used to calculate a unique check value for any electronic data. Most of these are messages. It should be virtually impossible to find two different messages with the same SHA value. This is also called collision freedom.
What is the difference between SHA1, SHA 256, SHA384 and SHA512?
The difference lies in the bit length of the created hash or the checksum. SHA1 hashes are only 160 bits long. Compared:
- SHA256 hashes are 256 bits long
- SHA384 hashes are 384 bits long
- SHA512 hashes are 512 bits
The larger the bit length, the less likely it is that the same checksum is randomly calculated for different inputs (see collision attack on SHA1).