Sha1 Encrypt & Decrypt

About Sha1 Online Decryption :

Sha1 is a cryptographic function that takes as input a 2^64 bits maximum length message, and outputs a 160 bits hash, 40 caracters. Sha1 is an improvement of Sha-0, it was created by the NSA, and improve cryptographic security by increasing the number of operations before a collision (theory says 2^63 operations), however Sha1 is not considered as secure because 2^63 could be reach pretty easily. It was replaced by Sha2 (224, 256, 384 and 512 bits), and more recently by Sha-3. Like Md5, Sha-1 is an unilateral function, to decrypt the plaintext behind a hash, you have to confront it to a online sha1 database. This website allows you to compare your Sha1 hashes and decrypt it online if you're lucky, thanks to our efficient online database. This database contains 15183605161 words, coming from all the wordlists I was able to find online. I then computed for days to enlarge the database and make it really unique, which will help you into Sha1 online decryption.
About security, Sha1 is not considered anymore as a secure hash type. If you still want to use it (and you should instead use Sha2 functions), you should consider using a salt to make hackers life harder. A salt consist in a string you add to the user password before hashing it. This string could be a random sequence, a timestamp, or anything that will make the password harder to be found.