Block Ciphers: ECB

The weakness of ECB is that patterns in the plaintext are repeated in the ciphertext, making it easy, if not obvious, to guess what the plaintext is hiding. Other, more secure modes, such as CBC make the plaintext unrecognizable.

Tux, the Linux penguin mascot. lewing@isc.tamu.edu Larry Ewing and The GIMP, CC0, via Wikimedia Commons.

Tux encrypted with ECB: we can clearly see Tux! lewing@isc.tamu.edu Larry Ewing and The GIMP, CC0, via Wikimedia Commons.

Tux encrypted with a different, more secure mode. Rumpelstilzchen 666, Public domain, via Wikimedia Commons.