Triple des decryption example

Thus option 3 with three identical keys is simply the original bit DEA algorithm with a keyspace of 56 bits, albeit done with three times as much effort. A DES key is 64 bits long, but only 56 bits of these are used in the encryption process. Note that if your "triple DES" key is not exactly bits long - i. The other 8 bits are meant to be used as error detecting or "parity" bits so, in principle, the validity of the key bit string can be checked every byte should be of odd parity , but this is hardly ever done.

Be careful, though, because this means that the keys represented, for example, by the following bit strings are treated as being equal, and will produce identical ciphertext output for the same plaintext input:. To comment on this page or for more information, please send us a message. Home Contact us. Active 7 months ago. Viewed 91k times. Thanks in advance! Improve this question. James James What's wrong with the one you link to? Is it just that it only handles 64 bit keys?

Wouldn't take much modification to fix that. Are you trying to implement the algorithm yourself for learning purposes I hope , or just how to do it with something like TripleDESCryptoServiceProvider? James: If you are needing cryptographic stuff then you should almost always use a prebuilt tried and tested bit of code to do your crypto for you.

One mistake by you in coding it could mean that you in fact have no security at all. Show 1 more comment. Active Oldest Votes. GetBytes toEncrypt ; System. Best Practice hashmd5. ToBase64String resultArray, 0, resultArray. FromBase64String cipherString ; System. Improve this answer. Bamdad 5 5 silver badges 18 18 bronze badges. Chris Gessler Chris Gessler ECB mode should not be used for encrypting strings.

Passwords are not strings, and only performing a single MD5 over the string does not provide much strength. Work nicely - only thing I would say is in the Decrypt method, the variable "toEncryptArray" should be called "toDecryptArray" - yes very picky, but when you are reading the code it avoids confusion. Add a comment. Configuration; using System. Cryptography; using System. TransformFinalBlock input, 0, input. Length ; return Convert.

Length ; return Encoding. ComputeHash Encoding. GetBytes key ; des. PKCS7; des. Godwin Awojobi Godwin Awojobi 77 1 1 silver badge 3 3 bronze badges. Great answer. Very clear example without a lot of fluff. Open, FileAccess. OpenOrCreate, FileAccess. Write ; fout. Write ; Console. WriteLine "Encrypting Read bin, 0, ; encStream. Owais Qureshi Owais Qureshi 4, 5 5 gold badges 37 37 silver badges 59 59 bronze badges. I would not suggest rolling your own, even for a well-defined algorithm like TDES.