SHA-1 reverse for fa765dd0e027a5aa062f57c73b81b54a66a9e280

The SHA-1 hash:
fa765dd0e027a5aa062f57c73b81b54a66a9e280
was succesfully reversed into the string:
90fa01b9e9dddff430f73f9251efeed5ad37c87a

Feel free to provide some other SHA-1 hashes you would like to try to reverse.

Reverse a SHA-1 hash

You can generate the SHA-1 hash of the string which was just reversed to have the proof that it is the same as the SHA-1 hash you provided:

Convert a string to a SHA-1 hash

What is a SHA-1 hash?

SHA-1 (Secure Hash Algorithm, 1st version) is an algorithm which converts a given sequence of characters into another unique sequence of characters, with a fixed length, called "hash". For instance, the SHA-1 hash of the word password is 5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8.

These hashes are mostly used to validate file integrity, to encrypt sensitive data (like passwords), and to generate unique identifiers.

Is it secure?

SHA-1 hashes are theoretically impossible to reverse directly, ie, it is not possible to retrieve the original string from a given hash using only mathematical operations.

Most web sites and applications store their user passwords into databases with SHA-1 encryption. This method appears to be safe as it seems impossible to retrieve original user passwords if, say, a hacker manages to have a look at the database content.

Unfortunately, there is a way to decrypt a SHA-1 hash, using a dictionary populated with strings and their SHA-1 counterpart. As most users use very simple passwords (like "123456", "password", "abc123", etc), SHA-1 dictionaries make them very easy to retrieve.

This website uses a SHA-1 reverse dictionary containing several millions of entries, which you can use with SHA-1 hashes from your application.

If some of the hashes you enter can be reversed, consider using another way of generating hashes, like using stronger algorithms (SHA-2, Whirlpool, etc), combining algorithms, and using a "salt".