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Why are encryption algorithms such as DES or AES not used for storing passwords?
Because AES encryption is symmetric. Given a password encrypted with AES and the key, you can decrypt the password. This is undesirable, because you almost always want only the owner of the password to know it and don’t want to have an easy way to derive the password.
Why 3DES is not secure?
However, Triple DES has a really “small” blocksize with only 64 bits, which led to attack such as Sweet32 against TLS session which allows to break the security of the system thanks to “block collision”. This attack led to the removal of Triple DES from the DEFAULT cipher list in the 1.1.
How does Feistel cipher work?
In a Feistel cipher, encryption and decryption are very similar operations, and both consist of iteratively running a function called a “round function” a fixed number of times.
Why is 3DES weak?
The 3DES cipher suffers from a fundamental weakness linked to its small (64-bit) blocksize, i.e. the size of plaintext that it can encrypt. In the common mode of operation CBC, each plaintext block is XORed with the previous ciphertext before encryption.
How much data can be encrypted by 3DES?
According to SP 800-67 Rev. 2, the amount of data to be encrypted by by a single, 3-key set must be limited to 8Gb. Also, the version of 3DES that uses only two unique keys is now entirely deprecated.
Why is the 3DES algorithm being phased out?
The reason 3DES is being phased out is due to various vulnerabilities (e.g. collision attacks like sweet32). While there are still ways to compensate (e.g. frequent rekey, disabling CBC mode) to prolong its life, there is no good reason not to switch to AES.
Is the 3DES algorithm secure according to NIST?
NIST still recognizes 3DES (ANSI X9.52-1998) as a secure symmetric-key encryption algorithm when configured to operate as described in NIST SP 800-20. There are still Cryptographic Algorithm Validation Program (CAVP) certificates issued for 3DES in 2016.
Is there still a CAVP certificate for 3DES?
There are still Cryptographic Algorithm Validation Program (CAVP) certificates issued for 3DES in 2016. However, many open source projects (e.g. OpenSSL) and international certification standards (e.g. Common Criteria) already deprecated 3DES.