SHA-1 hash for « 4dd1c8afafceed237cca8a334b24fe09069e3771e416a749687af002b4de 844566fdef57ba9f76a17c2ca1472f08cbb7b595524310614d8f9044f7f5 49c422a0f10599ace22d443907db0d54d6bf726f1c42c27fe93b7d8a5980 0661353b73fd868adc2ab687a0fdc7cd6560f917a1392e6594b62554b8cc b844f766583 »

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".