Lattice attack are effective against cryptographic systems where the nonce is reusable or predictable. So in a scenario where the transactions have 5 characters in common, it will be much easy for attackers to exploit potential weaknesses.

Just like in your given scenario an attacker can collect enough samples in which the case study here is 10, then apply a technique known as lattice reduction algorithms (like the Lattice-based attack) to find the nonce k and possibly recover the private key which in conclusion having multiple transactions with 5 characters in common in the R value posses a potential risk.

This could be due to:

• Nonce reuse
• Attackers control
• poor implementation ramdom of random number generator