3.10.1.3 Randomized CBC Mode
The "rcbc" encryption mode is CBC mode with randomized IV. This means
-that each IV for each packet MUST be chosen randomly (same IV is used
-to encrypt all blocks in the given packet). In this mode the IV is
-appended at the end of the last ciphertext block and thus delivered to
-the recipient. This mode increases the ciphertext size by one
-ciphertext block. Note also that some data payloads in SILC are capable
-of delivering the IV to the recipient. When explicitly encrypting these
-payloads with randomized CBC the IV MUST NOT be appended at the end
-of the ciphertext.
+that each IV for each packet MUST be chosen randomly. When encrypting
+more than one block the normal inter-packet chaining is used, but for
+the first block new random IV is selected in each packet. In this mode
+the IV is appended at the end of the last ciphertext block and thus
+delivered to the recipient. This mode increases the ciphertext size by
+one ciphertext block. Note also that some data payloads in SILC are
+capable of delivering the IV to the recipient. When explicitly
+encrypting these payloads with randomized CBC the IV MUST NOT be appended
+at the end of the ciphertext.
.ti 0