Consider the following encryption scheme. It supports plaintexts from $M=\{0,1{\}}^{}$ and

ciphertexts from $C=\{0,1{\}}^2.$ Its keyspace is:

To encrypt plaintext $m$ under key $k,$ we "fill in$"$ the $-$ characters in $k$ using the bits of $m.$

Show that the scheme does not have one$-$time secrecy$,$ by constructing a program that

distinguishes the two relevant libraries from the one$-$time secrecy definition.

Example: Below is an example encryption of $m=1101100001.$

$k=1_{--}{0}_{--}{11010}_1{?}_0{?}_0{?}_{---}$

$m=1101,100001$

$=>$Enc$(k,m)=11100111010110000001$