Military apply the concept **“security the obscurity”** and the key length is important but it is not always the case, for example:
 
1.	  Chiasmus cipher (secret German cipher leaked by reverse engineering) used 64-bit plaintext ,160-bit key length and ECB mode.
2.	Red pike  block cipher uses  64-bit block size and 64-bit key length (leaked on Cypherpunk)


Industry tend to use standards mainly AES (highly respected as a strong cipher and received many public analysis) especially when cryptography is not their core business.