Strong cipher algorithms are cryptographic systems resistant to cryptanalysis, they are not vulnerable to well-known attacks like brute force attacks for example.
A general recomandation is to only use cipher algorithms intensively tested and promoted by the cryptographic community.
More specifically for block cipher, it's not recommended to use algorithm with a block size inferior than 128 bits.
import javax.crypto.Cipher; import java.security.NoSuchAlgorithmException; import javax.crypto.NoSuchPaddingException; public class test { public static void main(String[] args) { try { Cipher c1 = Cipher.getInstance("DES"); // Noncompliant: DES works with 56-bit keys allow attacks via exhaustive search Cipher c7 = Cipher.getInstance("DESede"); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack Cipher c13 = Cipher.getInstance("RC2"); // Noncompliant: RC2 is vulnerable to a related-key attack Cipher c19 = Cipher.getInstance("RC4"); // Noncompliant: vulnerable to several attacks (see https://en.wikipedia.org/wiki/RC4#Security) Cipher c25 = Cipher.getInstance("Blowfish"); // Noncompliant: Blowfish use a 64-bit block size makes it vulnerable to birthday attacks NullCipher nc = new NullCipher(); // Noncompliant: the NullCipher class provides an "identity cipher" one that does not transform or encrypt the plaintext in any way. } catch(NoSuchAlgorithmException|NoSuchPaddingException e) { } } }
import javax.crypto.Cipher; import java.security.NoSuchAlgorithmException; import javax.crypto.NoSuchPaddingException; public class test { public static void main(String[] args) { try { Cipher c31 = Cipher.getInstance("AES/GCM/NoPadding"); // Compliant } catch(NoSuchAlgorithmException|NoSuchPaddingException e) { } } }